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Author SHA1 Message Date
Niels Lohmann 6f971ae520 Build the update()/merge_patch() diagnostics test values instead of parsing them
Parsed values carry byte positions under JSON_DIAGNOSTIC_POSITIONS, which
the expected messages do not include.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-24 17:11:39 +02:00
Niels Lohmann 3395089b5f Use the shared recursion limit in update() and merge_patch()
merge_depth_limit() is gone in favor of detail::recursion_depth_limit().
The two identical function-local frame structs become one member struct,
merge_frame, with a constructor, so both loops emplace_back() their
frames. merge_patch_iteratively() copies the frame it works on out of the
stack and changes it only through stack.back().

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-24 17:11:39 +02:00
Niels Lohmann 519094151e Merge deeply nested objects without recursing per nesting level
merge_patch() and update(j, true) merged a nested object by calling
themselves on it, once per nesting level. A value nested deeply enough -
50,000 levels of objects on an 8 MiB stack - exhausted the call stack
and terminated the process, although parse() accepts such values without
complaint.

Bound the descent the same way dump() does. The recursion now carries
the nesting level, and once merge_depth_limit() (128) levels have been
entered, update_members_iteratively() and merge_patch_iteratively()
finish the merge on an explicit stack. They still merge a nested object
completely before the next member, and in the same order, so the results,
including the parents JSON_DIAGNOSTICS reports paths from, are unchanged.
Values nested less deeply than the bound run the same code as before, so
the common case does not pay for the stack: merging only on it cost
10-14% in a first version.

The public signatures are unchanged. The recursive worker behind
merge_patch() has its own name rather than being a private overload, so
that &basic_json::merge_patch stays unambiguous.

Tests check every depth up to 300 against recursive reference
implementations of both operations, check the diagnostic paths past the
bound, and merge objects nested 100,000 levels deep.

Fixes #5545 for update(j, true), and #5393 for merge_patch().

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-24 17:11:39 +02:00
Niels Lohmann e9af5cbd11 Parenthesize multiplications in the hash test for clang-tidy
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-24 17:11:38 +02:00
Niels Lohmann 21c626c641 Share one recursion depth limit, and copy the hash frame out of the stack
dump() and hash() each defined their own limit on how many nesting levels
they recurse into, and the operations still to come would have added more,
free to diverge over time. They now all use detail::recursion_depth_limit(),
in a header of its own; serializer::dump_depth_limit() and
hash_depth_limit() are gone.

hash_iteratively() now copies the frame it works on out of the stack and
changes the frame only through stack.back(), so nothing can refer into
the stack after entering an element has grown it.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-24 17:11:38 +02:00
Niels Lohmann 00bfe6808b Declare hash_frame's constructor noexcept
GCC's -Wnoexcept (an error in CI) flags the emplace_back() into the
hash stack under C++26: the constructor cannot throw, since cbegin() is
noexcept, but it did not say so. dump_frame's constructor is noexcept
for the same reason.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-24 17:11:38 +02:00
Niels Lohmann 9be5018748 Hash deeply nested values without recursing per nesting level
std::hash<basic_json> hashed an array or object by hashing each element,
which called detail::hash again once per nesting level. A value nested
deeply enough - 50,000 levels of objects on an 8 MiB stack - exhausted
the call stack and terminated the process. parse() accepts such values
without complaint, since the parser is iterative, and a parsed value is
hashed wherever it is used as a key in an unordered container.

Bound the descent the same way dump() does: detail::hash takes the
nesting level, and once hash_depth_limit() (128) levels have been entered,
hash_iteratively() hashes what is left on an explicit stack. It combines
the seeds in exactly the same order, so hash values are unchanged. A value
nested less deeply than the bound is hashed by the same code as before,
without allocating, and is as fast as before.

Tests check that every depth up to twice the bound hashes exactly like
the recursive definition of the hash, and that values nested 100,000
levels deep hash without crashing.

Fixes #5545 for std::hash.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-24 17:11:38 +02:00
419 changed files with 1643 additions and 45949 deletions
-1
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@@ -2,7 +2,6 @@
- [ ] The changes are described in detail, both the what and why.
- [ ] If applicable, an [existing issue](https://github.com/nlohmann/json/issues) is referenced.
- [ ] If applicable, a fixed [OSS-Fuzz](https://issues.oss-fuzz.com) issue is referenced as `OSS-Fuzz: <id>` (see [fuzz testing](https://github.com/nlohmann/json/blob/develop/tests/fuzzing.md#handling-oss-fuzz-reports)).
- [ ] The [Code coverage](https://coveralls.io/github/nlohmann/json) remained at 100%. A test case for every new line of code.
- [ ] If applicable, the [documentation](https://json.nlohmann.me) is updated.
- [ ] The source code is amalgamated by running `make amalgamate`.
+3 -14
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@@ -9,23 +9,12 @@ identified a security vulnerability in this repository, please use the GitHub Se
Until it is published, this draft security advisory will only be visible to the maintainers of this project. Other
users and teams may be added once the advisory is created.
We will send a first response within 14 days, indicating the next steps in handling your report. After the initial
reply to your report, we will keep you informed of the progress towards a fix and full announcement and may ask for
additional information or guidance.
We will send a response indicating the next steps in handling your report. After the initial reply to your report, we
will keep you informed of the progress towards a fix and full announcement and may ask for additional information or
guidance.
For vulnerabilities in third-party dependencies or modules, please report them directly to the respective maintainers.
## Disclosure and credit
Once a fix is released, we publish the security advisory and list the fixed vulnerability in the release notes. We
credit the reporter in both, unless they ask not to be named.
## Supported versions
Security fixes are made on the `develop` branch and shipped with the next release. Only the latest release receives
security fixes; they are not backported to older releases. A release stops receiving security fixes when the next
release is published, so please update to the latest release to get them.
## Unofficial packages
This project does not publish an official npm package. The npm package
+4 -22
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@@ -37,31 +37,13 @@ labels:
files:
- "include/nlohmann/detail/input/binary_reader\\.hpp"
- "include/nlohmann/detail/output/binary_writer\\.hpp"
- "tests/src/unit-(bson|cbor|msgpack|ubjson|bjdata|bon8|binary_formats)"
- "tests/src/fuzzer-parse_(bson|cbor|msgpack|ubjson|bjdata|bon8)"
- "tests/src/unit-(bson|cbor|msgpack|ubjson|bjdata|binary_formats)"
- "tests/src/fuzzer-parse_(bson|cbor|msgpack|ubjson|bjdata)"
- "docs/mkdocs/docs/features/binary_formats/"
- "docs/mkdocs/docs/(api/basic_json|examples)/(to|from)_(bson|cbor|msgpack|ubjson|bjdata|bon8)"
- "docs/mkdocs/docs/(api/basic_json|examples)/(to|from)_(bson|cbor|msgpack|ubjson|bjdata)"
- label: "aspect: binary formats"
title: "(?i)(bson|cbor|msgpack|messagepack|ubjson|bjdata|bon8|binary format)"
- label: "aspect: json_view"
files:
- "include/nlohmann/json_view\\.hpp"
- "include/nlohmann/detail/view/.*"
- "single_include/nlohmann/json_view\\.hpp"
- "tests/src/unit-json_view.*"
- "tests/src/fuzzer-(parse_json_view|json_view_image)\\.cpp"
- "tests/benchmarks/json_view/.*"
- "tools/amalgamate/config_json_view\\.json"
- "docs/mkdocs/docs/features/json_view\\.md"
- "docs/mkdocs/docs/api/basic_json_(document|view)/.*"
- "docs/mkdocs/docs/api/(ordered_)?json_(editable_)?(document|view)\\.md"
- "docs/mkdocs/docs/examples/(basic_json_(document|view)__|(ordered_)?json_(editable_)?(document|view)).*"
- "tests/benchmarks/src/benchmarks_view\\.cpp"
- label: "aspect: json_view"
title: "(?i)(json_view|json_document|zero-copy)"
title: "(?i)(bson|cbor|msgpack|messagepack|ubjson|bjdata|binary format)"
- label: "python"
files:
+1 -6
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@@ -3,10 +3,6 @@ name: "Check amalgamation"
on:
pull_request:
concurrency:
group: ${{ github.workflow }}-${{ github.ref || github.run_id }}
cancel-in-progress: true
permissions:
contents: read
@@ -67,13 +63,12 @@ jobs:
python3 $TOOL_DIR/amalgamate.py -c $TOOL_DIR/config_json.json -s .
python3 $TOOL_DIR/amalgamate.py -c $TOOL_DIR/config_json_fwd.json -s .
python3 $TOOL_DIR/amalgamate.py -c $TOOL_DIR/config_json_view.json -s .
# the header list of the Bazel "json" target must match the files in include/
cmake -P cmake/scripts/gen_bazel_build_file.cmake
${{ github.workspace }}/venv/bin/astyle --project=tools/astyle/.astylerc --suffix=none --quiet \
$INCLUDE_DIR/json.hpp $INCLUDE_DIR/json_fwd.hpp $INCLUDE_DIR/json_view.hpp
$INCLUDE_DIR/json.hpp $INCLUDE_DIR/json_fwd.hpp
# fail loudly if a directory is renamed or removed: find would only warn
# about the missing path and silently drop its files from the check
-4
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@@ -1,10 +1,6 @@
name: CIFuzz
on: [pull_request]
concurrency:
group: ${{ github.workflow }}-${{ github.ref || github.run_id }}
cancel-in-progress: true
permissions:
contents: read
+3 -3
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@@ -38,14 +38,14 @@ jobs:
# Initializes the CodeQL tools for scanning.
- name: Initialize CodeQL
uses: github/codeql-action/init@1c5b675653bb5c22dbe9b12b556ec555138e09fd # v4.38.1
uses: github/codeql-action/init@b96794f015dfd88f77b49b1c93e0fa7110f94c63 # v4.38.0
with:
languages: c-cpp
# Autobuild attempts to build any compiled languages (C/C++, C#, or Java).
# If this step fails, then you should remove it and run the build manually (see below)
- name: Autobuild
uses: github/codeql-action/autobuild@1c5b675653bb5c22dbe9b12b556ec555138e09fd # v4.38.1
uses: github/codeql-action/autobuild@b96794f015dfd88f77b49b1c93e0fa7110f94c63 # v4.38.0
- name: Perform CodeQL Analysis
uses: github/codeql-action/analyze@1c5b675653bb5c22dbe9b12b556ec555138e09fd # v4.38.1
uses: github/codeql-action/analyze@b96794f015dfd88f77b49b1c93e0fa7110f94c63 # v4.38.0
-4
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@@ -9,10 +9,6 @@
name: 'Dependency Review'
on: [pull_request]
concurrency:
group: ${{ github.workflow }}-${{ github.ref || github.run_id }}
cancel-in-progress: true
permissions:
contents: read
+1 -5
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@@ -5,10 +5,6 @@
name: flawfinder
concurrency:
group: ${{ github.workflow }}-${{ github.ref || github.run_id }}
cancel-in-progress: true
permissions:
contents: read
@@ -47,6 +43,6 @@ jobs:
output: 'flawfinder_results.sarif'
- name: Upload analysis results to GitHub Security tab
uses: github/codeql-action/upload-sarif@1c5b675653bb5c22dbe9b12b556ec555138e09fd # v4.38.1
uses: github/codeql-action/upload-sarif@b96794f015dfd88f77b49b1c93e0fa7110f94c63 # v4.38.0
with:
sarif_file: ${{github.workspace}}/flawfinder_results.sarif
@@ -1,78 +0,0 @@
name: "json_view benchmarks"
# On demand only: runs the comparison of json_view with yyjson, simdjson, and
# Boost.JSON (tests/benchmarks/json_view/compare.py) on GitHub-hosted runners,
# for numbers from x86-64 and AArch64 Linux. It runs when started by hand, or
# when a pull request gets the label "benchmark" (on both architectures, with
# GCC and the default settings). Shared runners are noisy: the results show
# where json_view stands, but published numbers need a quiet machine (see
# tests/benchmarks/json_view/README.md).
on:
pull_request:
types: [labeled]
workflow_dispatch:
inputs:
runner:
description: "Runner image"
type: choice
options:
- ubuntu-24.04
- ubuntu-24.04-arm
default: ubuntu-24.04
compiler:
description: "Compiler"
type: choice
options:
- g++
- clang++
default: g++
native:
description: "Compile for the runner's CPU (-march=native)"
type: boolean
default: false
rounds:
description: "Rounds of bench_view"
type: number
default: 30
permissions:
contents: read
jobs:
compare:
if: github.event_name == 'workflow_dispatch' || github.event.label.name == 'benchmark'
strategy:
matrix:
runner: ${{ fromJSON(github.event_name == 'workflow_dispatch' && format('["{0}"]', inputs.runner) || '["ubuntu-24.04", "ubuntu-24.04-arm"]') }}
runs-on: ${{ matrix.runner }}
steps:
- name: Harden Runner
uses: step-security/harden-runner@e14015d583714f6e62063499dc959a02595150a1 # v2.21.1
with:
egress-policy: audit
- uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
with:
persist-credentials: false
- name: Download test data
run: |
cmake -S . -B build -DJSON_BuildTests=On
cmake --build build --target download_test_data
- name: Run the comparison
env:
CXX: ${{ inputs.compiler || 'g++' }}
CC: ${{ inputs.compiler == 'clang++' && 'clang' || 'gcc' }}
ROUNDS: ${{ inputs.rounds || 30 }}
NATIVE: ${{ inputs.native && '--native' || '' }}
run: python3 tests/benchmarks/json_view/compare.py --data build/test_files --download --rounds "$ROUNDS" $NATIVE
- name: Summary
run: cat tests/benchmarks/json_view/results/*.md >> "$GITHUB_STEP_SUMMARY"
- uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
with:
name: json_view-benchmarks-${{ matrix.runner }}-${{ inputs.compiler || 'g++' }}
path: tests/benchmarks/json_view/results/
-6
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@@ -4,12 +4,6 @@ on:
pull_request_target:
types: [opened, synchronize]
# pull_request_target runs on the base branch, so github.ref would put all pull
# requests into one group; group by pull request number instead
concurrency:
group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.run_id }}
cancel-in-progress: true
permissions:
contents: read
+1 -5
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@@ -14,10 +14,6 @@ on:
push:
branches: ["develop"]
concurrency:
group: ${{ github.workflow }}-${{ github.ref || github.run_id }}
cancel-in-progress: true
permissions:
contents: read
@@ -80,6 +76,6 @@ jobs:
# Upload the results to GitHub's code scanning dashboard.
- name: "Upload to code-scanning"
uses: github/codeql-action/upload-sarif@1c5b675653bb5c22dbe9b12b556ec555138e09fd # v4.38.1
uses: github/codeql-action/upload-sarif@b96794f015dfd88f77b49b1c93e0fa7110f94c63 # v4.38.0
with:
sarif_file: results.sarif
+1 -5
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@@ -19,10 +19,6 @@ on:
schedule:
- cron: '23 2 * * 4'
concurrency:
group: ${{ github.workflow }}-${{ github.ref || github.run_id }}
cancel-in-progress: true
permissions:
contents: read
@@ -65,7 +61,7 @@ jobs:
# Upload SARIF file generated in previous step
- name: Upload SARIF file
uses: github/codeql-action/upload-sarif@1c5b675653bb5c22dbe9b12b556ec555138e09fd # v4.38.1
uses: github/codeql-action/upload-sarif@b96794f015dfd88f77b49b1c93e0fa7110f94c63 # v4.38.0
with:
sarif_file: semgrep.sarif
if: always()
+2 -2
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@@ -124,11 +124,11 @@ jobs:
steps:
- uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
- name: Run CMake (Release)
run: cmake -S . -B build -G "Visual Studio 18 2026" -A ARM64 -DJSON_BuildTests=On -DCMAKE_CXX_FLAGS="/W4 /WX"
run: cmake -S . -B build -G "Visual Studio 17 2022" -A ARM64 -DJSON_BuildTests=On -DCMAKE_CXX_FLAGS="/W4 /WX"
if: matrix.build_type == 'Release'
shell: pwsh
- name: Run CMake (Debug)
run: cmake -S . -B build -G "Visual Studio 18 2026" -A ARM64 -DJSON_BuildTests=On -DJSON_FastTests=ON -DCMAKE_CXX_FLAGS="/W4 /WX"
run: cmake -S . -B build -G "Visual Studio 17 2022" -A ARM64 -DJSON_BuildTests=On -DJSON_FastTests=ON -DCMAKE_CXX_FLAGS="/W4 /WX"
if: matrix.build_type == 'Debug'
shell: pwsh
- name: Build
+1 -27
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@@ -20,9 +20,7 @@ cc_library(
hdrs = [
"include/nlohmann/adl_serializer.hpp",
"include/nlohmann/byte_container_with_subtype.hpp",
"include/nlohmann/detail/abi_config.hpp",
"include/nlohmann/detail/abi_macros.hpp",
"include/nlohmann/detail/bit_ops.hpp",
"include/nlohmann/detail/conversions/from_json.hpp",
"include/nlohmann/detail/conversions/to_chars.hpp",
"include/nlohmann/detail/conversions/to_json.hpp",
@@ -35,7 +33,6 @@ cc_library(
"include/nlohmann/detail/input/number_parse.hpp",
"include/nlohmann/detail/input/parser.hpp",
"include/nlohmann/detail/input/position_t.hpp",
"include/nlohmann/detail/input/pow5_table.hpp",
"include/nlohmann/detail/input/string_scan.hpp",
"include/nlohmann/detail/iterators/internal_iterator.hpp",
"include/nlohmann/detail/iterators/iter_impl.hpp",
@@ -66,44 +63,21 @@ cc_library(
"include/nlohmann/detail/string_escape.hpp",
"include/nlohmann/detail/string_utils.hpp",
"include/nlohmann/detail/value_t.hpp",
"include/nlohmann/detail/view/builder.hpp",
"include/nlohmann/detail/view/compare.hpp",
"include/nlohmann/detail/view/document_data.hpp",
"include/nlohmann/detail/view/edit.hpp",
"include/nlohmann/detail/view/edit_storage.hpp",
"include/nlohmann/detail/view/errors.hpp",
"include/nlohmann/detail/view/image.hpp",
"include/nlohmann/detail/view/input.hpp",
"include/nlohmann/detail/view/iterator.hpp",
"include/nlohmann/detail/view/lookup.hpp",
"include/nlohmann/detail/view/macro_scope.hpp",
"include/nlohmann/detail/view/macro_unscope.hpp",
"include/nlohmann/detail/view/materialize.hpp",
"include/nlohmann/detail/view/node.hpp",
"include/nlohmann/detail/view/number.hpp",
"include/nlohmann/detail/view/object_index.hpp",
"include/nlohmann/detail/view/pointer.hpp",
"include/nlohmann/detail/view/scan.hpp",
"include/nlohmann/detail/view/serializer.hpp",
"include/nlohmann/detail/view/simd.hpp",
"include/nlohmann/detail/view/string_ref.hpp",
"include/nlohmann/detail/view/value.hpp",
"include/nlohmann/json.hpp",
"include/nlohmann/json_fwd.hpp",
"include/nlohmann/json_view.hpp",
"include/nlohmann/ordered_map.hpp",
"include/nlohmann/thirdparty/hedley/hedley.hpp",
"include/nlohmann/thirdparty/hedley/hedley_undef.hpp",
],
includes = ["include"],
visibility = ["//visibility:public"],
alwayslink = True,
)
cc_library(
name = "singleheader-json",
hdrs = [
"single_include/nlohmann/json.hpp",
"single_include/nlohmann/json_view.hpp",
],
includes = ["single_include"],
visibility = ["//visibility:public"],
+6 -34
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@@ -21,7 +21,6 @@ TESTS_SRCS=$(shell find tests -type f \( -name '*.hpp' -o -name '*.cpp' -o -name
# the single headers (amalgamated from the source files)
AMALGAMATED_FILE=single_include/nlohmann/json.hpp
AMALGAMATED_FWD_FILE=single_include/nlohmann/json_fwd.hpp
AMALGAMATED_VIEW_FILE=single_include/nlohmann/json_view.hpp
##########################################################################
@@ -30,17 +29,15 @@ AMALGAMATED_VIEW_FILE=single_include/nlohmann/json_view.hpp
# main target
all:
@echo "amalgamate - amalgamate files single_include/nlohmann/json{,_fwd,_view}.hpp from the include/nlohmann sources"
@echo "amalgamate - amalgamate files single_include/nlohmann/json{,_fwd}.hpp from the include/nlohmann sources"
@echo "BUILD.bazel - regenerate the Bazel BUILD file from the include/nlohmann sources"
@echo "ChangeLog.md - generate ChangeLog file"
@echo "check-amalgamation - check whether sources have been amalgamated and BUILD.bazel is up to date"
@echo "clean - remove built files"
@echo "doctest - compile example files and check their output"
@echo "fuzz_testing - prepare fuzz testing of the JSON parser"
@echo "fuzz_testing_bon8 - prepare fuzz testing of the BON8 parser"
@echo "fuzz_testing_bson - prepare fuzz testing of the BSON parser"
@echo "fuzz_testing_cbor - prepare fuzz testing of the CBOR parser"
@echo "fuzz_testing_json_view - prepare fuzz testing of the json_document/json_view parser"
@echo "fuzz_testing_msgpack - prepare fuzz testing of the MessagePack parser"
@echo "fuzz_testing_ubjson - prepare fuzz testing of the UBJSON parser"
@echo "pretty - beautify code with Artistic Style"
@@ -74,14 +71,6 @@ fuzz_testing:
find tests/data/json_tests -size -5k -name *json | xargs -I{} cp "{}" fuzz-testing/testcases
@echo "Execute: afl-fuzz -i fuzz-testing/testcases -o fuzz-testing/out fuzz-testing/fuzzer"
fuzz_testing_bon8:
rm -fr fuzz-testing
mkdir -p fuzz-testing fuzz-testing/testcases fuzz-testing/out
$(MAKE) parse_bon8_fuzzer -C tests CXX=afl-clang++
mv tests/parse_bon8_fuzzer fuzz-testing/fuzzer
find tests/data -size -5k -name *.bon8 | xargs -I{} cp "{}" fuzz-testing/testcases
@echo "Execute: afl-fuzz -i fuzz-testing/testcases -o fuzz-testing/out fuzz-testing/fuzzer"
fuzz_testing_bson:
rm -fr fuzz-testing
mkdir -p fuzz-testing fuzz-testing/testcases fuzz-testing/out
@@ -98,14 +87,6 @@ fuzz_testing_cbor:
find tests/data -size -5k -name *.cbor | xargs -I{} cp "{}" fuzz-testing/testcases
@echo "Execute: afl-fuzz -i fuzz-testing/testcases -o fuzz-testing/out fuzz-testing/fuzzer"
fuzz_testing_json_view:
rm -fr fuzz-testing
mkdir -p fuzz-testing fuzz-testing/testcases fuzz-testing/out
$(MAKE) parse_json_view_fuzzer -C tests CXX=afl-clang++
mv tests/parse_json_view_fuzzer fuzz-testing/fuzzer
find tests/data/json_tests -size -5k -name *json | xargs -I{} cp "{}" fuzz-testing/testcases
@echo "Execute: afl-fuzz -i fuzz-testing/testcases -o fuzz-testing/out fuzz-testing/fuzzer"
fuzz_testing_msgpack:
rm -fr fuzz-testing
mkdir -p fuzz-testing fuzz-testing/testcases fuzz-testing/out
@@ -164,14 +145,14 @@ install_astyle:
# call the Artistic Style pretty printer on all source files
pretty: install_astyle
$(ASTYLE) --project=tools/astyle/.astylerc $(SRCS) $(TESTS_SRCS) $(AMALGAMATED_FILE) $(AMALGAMATED_FWD_FILE) $(AMALGAMATED_VIEW_FILE) docs/mkdocs/docs/examples/*.cpp
$(ASTYLE) --project=tools/astyle/.astylerc $(SRCS) $(TESTS_SRCS) $(AMALGAMATED_FILE) $(AMALGAMATED_FWD_FILE) docs/mkdocs/docs/examples/*.cpp
# call the Clang-Format on all source files
pretty_format:
for FILE in $(SRCS) $(TESTS_SRCS) $(AMALGAMATED_FILE) docs/mkdocs/docs/examples/*.cpp; do echo $$FILE; clang-format -i $$FILE; done
# create single header files and pretty print
amalgamate: $(AMALGAMATED_FILE) $(AMALGAMATED_FWD_FILE) $(AMALGAMATED_VIEW_FILE)
amalgamate: $(AMALGAMATED_FILE) $(AMALGAMATED_FWD_FILE)
$(MAKE) pretty
# call the amalgamation tool for json.hpp
@@ -182,23 +163,16 @@ $(AMALGAMATED_FILE): $(SRCS)
$(AMALGAMATED_FWD_FILE): $(SRCS)
tools/amalgamate/amalgamate.py -c tools/amalgamate/config_json_fwd.json -s . --verbose=yes
# call the amalgamation tool for json_view.hpp (keeps including json.hpp)
$(AMALGAMATED_VIEW_FILE): $(SRCS)
tools/amalgamate/amalgamate.py -c tools/amalgamate/config_json_view.json -s . --verbose=yes
# check if file single_include/nlohmann/json.hpp has been amalgamated from the nlohmann sources
# Note: this target is called by Travis
check-amalgamation:
@mv $(AMALGAMATED_FILE) $(AMALGAMATED_FILE)~
@mv $(AMALGAMATED_FWD_FILE) $(AMALGAMATED_FWD_FILE)~
@mv $(AMALGAMATED_VIEW_FILE) $(AMALGAMATED_VIEW_FILE)~
@$(MAKE) amalgamate
@diff $(AMALGAMATED_FILE) $(AMALGAMATED_FILE)~ || (echo "===================================================================\n Amalgamation required! Please read the contribution guidelines\n in file .github/CONTRIBUTING.md.\n===================================================================" ; mv $(AMALGAMATED_FILE)~ $(AMALGAMATED_FILE) ; false)
@diff $(AMALGAMATED_FWD_FILE) $(AMALGAMATED_FWD_FILE)~ || (echo "===================================================================\n Amalgamation required! Please read the contribution guidelines\n in file .github/CONTRIBUTING.md.\n===================================================================" ; mv $(AMALGAMATED_FWD_FILE)~ $(AMALGAMATED_FWD_FILE) ; false)
@diff $(AMALGAMATED_VIEW_FILE) $(AMALGAMATED_VIEW_FILE)~ || (echo "===================================================================\n Amalgamation required! Please read the contribution guidelines\n in file .github/CONTRIBUTING.md.\n===================================================================" ; mv $(AMALGAMATED_VIEW_FILE)~ $(AMALGAMATED_VIEW_FILE) ; false)
@mv $(AMALGAMATED_FILE)~ $(AMALGAMATED_FILE)
@mv $(AMALGAMATED_FWD_FILE)~ $(AMALGAMATED_FWD_FILE)
@mv $(AMALGAMATED_VIEW_FILE)~ $(AMALGAMATED_VIEW_FILE)
@mv BUILD.bazel BUILD.bazel~
@$(MAKE) BUILD.bazel
@diff BUILD.bazel BUILD.bazel~ || (echo "===================================================================\n BUILD.bazel is out of date! Please run 'make BUILD.bazel'.\n===================================================================" ; mv BUILD.bazel~ BUILD.bazel ; false)
@@ -239,7 +213,7 @@ json.tar.xz:
# We use `-X` to make the resulting ZIP file reproducible, see
# <https://content.pivotal.io/blog/barriers-to-deterministic-reproducible-zip-files>.
include.zip: BUILD.bazel
zip -9 --recurse-paths -X include.zip $(SRCS) $(AMALGAMATED_FILE) $(AMALGAMATED_FWD_FILE) $(AMALGAMATED_VIEW_FILE) BUILD.bazel MODULE.bazel meson.build LICENSE.MIT
zip -9 --recurse-paths -X include.zip $(SRCS) $(AMALGAMATED_FILE) $(AMALGAMATED_FWD_FILE) BUILD.bazel MODULE.bazel meson.build LICENSE.MIT
# Create the files for a release and add signatures and hashes.
release: include.zip json.tar.xz
@@ -248,13 +222,11 @@ release: include.zip json.tar.xz
gpg --armor --detach-sig include.zip
gpg --armor --detach-sig $(AMALGAMATED_FILE)
gpg --armor --detach-sig $(AMALGAMATED_FWD_FILE)
gpg --armor --detach-sig $(AMALGAMATED_VIEW_FILE)
gpg --armor --detach-sig json.tar.xz
cp $(AMALGAMATED_FILE) release_files
cp $(AMALGAMATED_FWD_FILE) release_files
cp $(AMALGAMATED_VIEW_FILE) release_files
mv $(AMALGAMATED_FILE).asc $(AMALGAMATED_FWD_FILE).asc $(AMALGAMATED_VIEW_FILE).asc json.tar.xz json.tar.xz.asc include.zip include.zip.asc release_files
cd release_files ; shasum -a 256 json.hpp json_view.hpp include.zip json.tar.xz > hashes.txt
mv $(AMALGAMATED_FILE).asc $(AMALGAMATED_FWD_FILE).asc json.tar.xz json.tar.xz.asc include.zip include.zip.asc release_files
cd release_files ; shasum -a 256 json.hpp include.zip json.tar.xz > hashes.txt
##########################################################################
+6 -25
View File
@@ -17,7 +17,7 @@
[![GitHub Downloads](https://img.shields.io/github/downloads/nlohmann/json/total)](https://github.com/nlohmann/json/releases)
[![GitHub Issues](https://img.shields.io/github/issues/nlohmann/json.svg)](https://github.com/nlohmann/json/issues)
[![Average time to resolve an issue](https://isitmaintained.com/badge/resolution/nlohmann/json.svg)](https://isitmaintained.com/project/nlohmann/json "Average time to resolve an issue")
[![OpenSSF Best Practices](https://www.bestpractices.dev/projects/289/badge)](https://www.bestpractices.dev/projects/289)
[![CII Best Practices](https://bestpractices.coreinfrastructure.org/projects/289/badge)](https://bestpractices.coreinfrastructure.org/projects/289)
[![OpenSSF Scorecard](https://api.scorecard.dev/projects/github.com/nlohmann/json/badge)](https://scorecard.dev/viewer/?uri=github.com/nlohmann/json)
[![Backup Status](https://app.cloudback.it/badge/nlohmann/json)](https://cloudback.it)
[![GitHub Sponsors](https://img.shields.io/badge/GitHub-Sponsors-ff69b4)](https://github.com/sponsors/nlohmann)
@@ -40,7 +40,7 @@
- [Implicit conversions](#implicit-conversions)
- [Conversions to/from arbitrary types](#arbitrary-types-conversions)
- [Specializing enum conversion](#specializing-enum-conversion)
- [Binary formats (BSON, CBOR, MessagePack, UBJSON, BJData, and BON8)](#binary-formats-bson-cbor-messagepack-ubjson-bjdata-and-bon8)
- [Binary formats (BSON, CBOR, MessagePack, UBJSON, and BJData)](#binary-formats-bson-cbor-messagepack-ubjson-and-bjdata)
- [Customers](#customers)
- [Ecosystem](#ecosystem)
- [Supported compilers](#supported-compilers)
@@ -63,7 +63,7 @@ There are myriads of [JSON](https://json.org) libraries out there, and each may
- **Trivial integration**. Our whole code consists of a single header file [`json.hpp`](https://github.com/nlohmann/json/blob/develop/single_include/nlohmann/json.hpp). That's it. No library, no subproject, no dependencies, no complex build system. The class is written in vanilla C++11. All in all, everything should require no adjustment of your compiler flags or project settings. The library is also included in all popular [package managers](https://json.nlohmann.me/integration/package_managers/).
- **Serious testing**. Our code is heavily [unit-tested](https://github.com/nlohmann/json/tree/develop/tests/src) and covers [100%](https://coveralls.io/r/nlohmann/json) of the code, including all exceptional behavior. Furthermore, we checked with [Valgrind](https://valgrind.org) and the [Clang Sanitizers](https://clang.llvm.org/docs/index.html) that there are no memory leaks. [Google OSS-Fuzz](https://github.com/google/oss-fuzz/tree/master/projects/json) additionally runs fuzz tests against all parsers 24/7, effectively executing billions of tests so far. To maintain high quality, the project is following the [OpenSSF Best Practices](https://www.bestpractices.dev/projects/289). See the [quality assurance](https://json.nlohmann.me/community/quality_assurance) overview documentation.
- **Serious testing**. Our code is heavily [unit-tested](https://github.com/nlohmann/json/tree/develop/tests/src) and covers [100%](https://coveralls.io/r/nlohmann/json) of the code, including all exceptional behavior. Furthermore, we checked with [Valgrind](https://valgrind.org) and the [Clang Sanitizers](https://clang.llvm.org/docs/index.html) that there are no memory leaks. [Google OSS-Fuzz](https://github.com/google/oss-fuzz/tree/master/projects/json) additionally runs fuzz tests against all parsers 24/7, effectively executing billions of tests so far. To maintain high quality, the project is following the [Core Infrastructure Initiative (CII) best practices](https://bestpractices.coreinfrastructure.org/projects/289). See the [quality assurance](https://json.nlohmann.me/community/quality_assurance) overview documentation.
Other aspects were not so important to us:
@@ -128,7 +128,7 @@ There is also a [**docset**](https://github.com/Kapeli/Dash-User-Contributions/t
- **JSON Pointer functions**: [flatten](https://json.nlohmann.me/api/basic_json/flatten), [unflatten](https://json.nlohmann.me/api/basic_json/unflatten)
- **JSON Patch functions**: [patch](https://json.nlohmann.me/api/basic_json/patch), [patch_inplace](https://json.nlohmann.me/api/basic_json/patch_inplace), [diff](https://json.nlohmann.me/api/basic_json/diff), [merge_patch](https://json.nlohmann.me/api/basic_json/merge_patch)
- **Static functions**: [meta](https://json.nlohmann.me/api/basic_json/meta), [get_allocator](https://json.nlohmann.me/api/basic_json/get_allocator)
- **Binary formats**: [from_bjdata](https://json.nlohmann.me/api/basic_json/from_bjdata), [from_bon8](https://json.nlohmann.me/api/basic_json/from_bon8), [from_bson](https://json.nlohmann.me/api/basic_json/from_bson), [from_cbor](https://json.nlohmann.me/api/basic_json/from_cbor), [from_msgpack](https://json.nlohmann.me/api/basic_json/from_msgpack), [from_ubjson](https://json.nlohmann.me/api/basic_json/from_ubjson), [to_bjdata](https://json.nlohmann.me/api/basic_json/to_bjdata), [to_bon8](https://json.nlohmann.me/api/basic_json/to_bon8), [to_bson](https://json.nlohmann.me/api/basic_json/to_bson), [to_cbor](https://json.nlohmann.me/api/basic_json/to_cbor), [to_msgpack](https://json.nlohmann.me/api/basic_json/to_msgpack), [to_ubjson](https://json.nlohmann.me/api/basic_json/to_ubjson)
- **Binary formats**: [from_bjdata](https://json.nlohmann.me/api/basic_json/from_bjdata), [from_bson](https://json.nlohmann.me/api/basic_json/from_bson), [from_cbor](https://json.nlohmann.me/api/basic_json/from_cbor), [from_msgpack](https://json.nlohmann.me/api/basic_json/from_msgpack), [from_ubjson](https://json.nlohmann.me/api/basic_json/from_ubjson), [to_bjdata](https://json.nlohmann.me/api/basic_json/to_bjdata), [to_bson](https://json.nlohmann.me/api/basic_json/to_bson), [to_cbor](https://json.nlohmann.me/api/basic_json/to_cbor), [to_msgpack](https://json.nlohmann.me/api/basic_json/to_msgpack), [to_ubjson](https://json.nlohmann.me/api/basic_json/to_ubjson)
- **Non-member functions**: [operator<<](https://json.nlohmann.me/api/operator_ltlt/), [operator>>](https://json.nlohmann.me/api/operator_gtgt/), [to_string](https://json.nlohmann.me/api/basic_json/to_string)
- **Literals**: [operator""_json](https://json.nlohmann.me/api/operator_literal_json)
- **Helper classes**: [std::hash&lt;basic_json&gt;](https://json.nlohmann.me/api/basic_json/std_hash), [std::swap&lt;basic_json&gt;](https://json.nlohmann.me/api/basic_json/std_swap)
@@ -1110,9 +1110,9 @@ Other Important points:
- When using `get<ENUM_TYPE>()`, undefined JSON values will default to the first pair specified in your map. Select this default pair carefully. If you desire an exception in this circumstance use `NLOHMANN_JSON_SERIALIZE_ENUM_STRICT()` which behaves identically except for throwing an exception on unrecognized values.
- If an enum or JSON value is specified more than once in your map, the first matching occurrence from the top of the map will be returned when converting to or from JSON.
### Binary formats (BSON, CBOR, MessagePack, UBJSON, BJData, and BON8)
### Binary formats (BSON, CBOR, MessagePack, UBJSON, and BJData)
Though JSON is a ubiquitous data format, it is not a very compact format suitable for data exchange, for instance over a network. Hence, the library supports [BSON](https://bsonspec.org) (Binary JSON), [CBOR](https://cbor.io) (Concise Binary Object Representation), [MessagePack](https://msgpack.org), [UBJSON](https://ubjson.org) (Universal Binary JSON Specification), [BJData](https://neurojson.org/bjdata) (Binary JData), and [BON8](https://github.com/hikoworks/hikogui/blob/main/docs/BON8.md) (Binary Object Notation 8) to efficiently encode JSON values to byte vectors and to decode such vectors.
Though JSON is a ubiquitous data format, it is not a very compact format suitable for data exchange, for instance over a network. Hence, the library supports [BSON](https://bsonspec.org) (Binary JSON), [CBOR](https://cbor.io) (Concise Binary Object Representation), [MessagePack](https://msgpack.org), [UBJSON](https://ubjson.org) (Universal Binary JSON Specification) and [BJData](https://neurojson.org/bjdata) (Binary JData) to efficiently encode JSON values to byte vectors and to decode such vectors.
```cpp
// create a JSON value
@@ -1149,14 +1149,6 @@ std::vector<std::uint8_t> v_ubjson = json::to_ubjson(j);
// roundtrip
json j_from_ubjson = json::from_ubjson(v_ubjson);
// serialize to BON8
std::vector<std::uint8_t> v_bon8 = json::to_bon8(j);
// 0x88, 0x63, 0x6F, 0x6D, 0x70, 0x61, 0x63, 0x74, 0xF9, 0x73, 0x63, 0x68, 0x65, 0x6D, 0x61, 0x90
// roundtrip
json j_from_bon8 = json::from_bon8(v_bon8);
```
The library also supports binary types from BSON, CBOR (byte strings), and MessagePack (bin, ext, fixext). They are stored by default as `std::vector<std::uint8_t>` to be processed outside the library.
@@ -1189,14 +1181,6 @@ binary.set_subtype(0x10);
auto cbor = json::to_msgpack(j); // 0xD5 (fixext2), 0x10, 0xCA, 0xFE
```
### Zero-copy views
Header `<nlohmann/json_view.hpp>` adds `json_document`/`json_view`, a read-only, non-owning way to look at a parsed
JSON text: parsing builds a flat index (16 bytes per value) instead of a tree, strings and numbers stay in the source
text, and `materialize()` builds a `json` value for a subtree only when you actually need one. See
[Zero-copy JSON views](https://json.nlohmann.me/features/json_view/) for the details, including which inputs are
borrowed and which are copied.
## Customers
The library is used in multiple projects, applications, operating systems, etc. The list below is not exhaustive, but the result of an internet search. If you know further customers of the library, please let me know, see [contact](#contact).
@@ -1403,9 +1387,6 @@ THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR I
- The class contains a slightly modified version of the Grisu2 algorithm from Florian Loitsch which is licensed under the [MIT License](https://opensource.org/licenses/MIT) (see above). Copyright &copy; 2009 [Florian Loitsch](https://florian.loitsch.com/)
- The class contains a copy of [Hedley](https://nemequ.github.io/hedley/) from Evan Nemerson which is licensed as [CC0-1.0](https://creativecommons.org/publicdomain/zero/1.0/).
- The class contains parts of [Google Abseil](https://github.com/abseil/abseil-cpp) which is licensed under the [Apache 2.0 License](https://opensource.org/licenses/Apache-2.0).
- The class contains an adapted version of the Eisel-Lemire algorithm and its table of powers of five from [fast_float](https://github.com/fastfloat/fast_float) by Daniel Lemire and contributors, which is available under the [MIT License](https://opensource.org/licenses/MIT) (used here), the Apache 2.0 License, and the Boost Software License. Copyright &copy; 2021 The fast_float authors
- The view's parser (`<nlohmann/json_view.hpp>`) contains techniques and code adapted from [yyjson](https://github.com/ibireme/yyjson) by YaoYuan, which is licensed under the [MIT License](https://opensource.org/licenses/MIT) (see above): table-driven decoding of `\u` escapes and fixed-offset unrolled checks.
- The view's parser (`<nlohmann/json_view.hpp>`) validates non-ASCII strings with the vector UTF-8 check of [simdjson](https://github.com/simdjson/simdjson) by Daniel Lemire, Geoff Langdale, John Keiser, and contributors (its "lookup4" algorithm and tables, after J. Keiser and D. Lemire, "Validating UTF-8 In Less Than One Instruction Per Byte", 2021), which is available under the [MIT License](https://opensource.org/licenses/MIT) (used here) and the Apache 2.0 License. Copyright &copy; 2018-2025 The simdjson authors
<img align="right" src="https://git.fsfe.org/reuse/reuse-ci/raw/branch/master/reuse-horizontal.png" alt="REUSE Software">
+8 -11
View File
@@ -300,10 +300,10 @@ add_custom_target(ci_test_skiplibraryversioncheck
# Disable thread-local storage.
###############################################################################
# Without thread-local storage, copying and comparing cannot bound their
# descent and handle every object and array without the call stack. Those paths
# are otherwise only reached by values nested deeper than the bound, so this
# target is what runs the whole test suite through them.
# Without thread-local storage, the copy constructor cannot bound its descent
# and copies every object and array without the call stack. That path is
# otherwise only reached by values nested deeper than the bound, so this target
# is what runs the whole test suite through it.
add_custom_target(ci_test_no_thread_local
COMMAND ${CMAKE_COMMAND}
-DCMAKE_BUILD_TYPE=Debug -GNinja
@@ -373,10 +373,9 @@ file(GLOB_RECURSE INDENT_FILES
set(include_dir ${PROJECT_SOURCE_DIR}/single_include/nlohmann)
set(tool_dir ${PROJECT_SOURCE_DIR}/tools/amalgamate)
add_custom_target(ci_test_amalgamation
COMMAND rm -fr ${include_dir}/json.hpp~ ${include_dir}/json_fwd.hpp~ ${include_dir}/json_view.hpp~
COMMAND rm -fr ${include_dir}/json.hpp~ ${include_dir}/json_fwd.hpp~
COMMAND cp ${include_dir}/json.hpp ${include_dir}/json.hpp~
COMMAND cp ${include_dir}/json_fwd.hpp ${include_dir}/json_fwd.hpp~
COMMAND cp ${include_dir}/json_view.hpp ${include_dir}/json_view.hpp~
COMMAND ${Python3_EXECUTABLE} -mvenv venv_astyle
COMMAND venv_astyle/bin/pip3 --quiet install -r ${CMAKE_SOURCE_DIR}/tools/astyle/requirements.txt
@@ -384,12 +383,10 @@ add_custom_target(ci_test_amalgamation
COMMAND ${Python3_EXECUTABLE} ${tool_dir}/amalgamate.py -c ${tool_dir}/config_json.json -s .
COMMAND ${Python3_EXECUTABLE} ${tool_dir}/amalgamate.py -c ${tool_dir}/config_json_fwd.json -s .
COMMAND ${Python3_EXECUTABLE} ${tool_dir}/amalgamate.py -c ${tool_dir}/config_json_view.json -s .
COMMAND venv_astyle/bin/astyle --project=tools/astyle/.astylerc --suffix=none ${include_dir}/json.hpp ${include_dir}/json_fwd.hpp ${include_dir}/json_view.hpp
COMMAND venv_astyle/bin/astyle --project=tools/astyle/.astylerc --suffix=none ${include_dir}/json.hpp ${include_dir}/json_fwd.hpp
COMMAND diff ${include_dir}/json.hpp~ ${include_dir}/json.hpp
COMMAND diff ${include_dir}/json_fwd.hpp~ ${include_dir}/json_fwd.hpp
COMMAND diff ${include_dir}/json_view.hpp~ ${include_dir}/json_view.hpp
COMMAND venv_astyle/bin/astyle --project=tools/astyle/.astylerc --suffix=orig ${INDENT_FILES}
COMMAND for FILE in `find . -name '*.orig'`\; do false \; done
@@ -545,7 +542,7 @@ add_custom_target(ci_infer
add_custom_target(ci_offline_testdata
COMMAND mkdir -p ${PROJECT_BINARY_DIR}/build_offline_testdata/test_data
COMMAND cd ${PROJECT_BINARY_DIR}/build_offline_testdata/test_data && ${GIT_TOOL} clone -c advice.detachedHead=false --branch v3.2.0 https://github.com/nlohmann/json_test_data.git --quiet --depth 1
COMMAND cd ${PROJECT_BINARY_DIR}/build_offline_testdata/test_data && ${GIT_TOOL} clone -c advice.detachedHead=false --branch v3.1.0 https://github.com/nlohmann/json_test_data.git --quiet --depth 1
COMMAND ${CMAKE_COMMAND}
-DCMAKE_BUILD_TYPE=Debug -GNinja
-DJSON_BuildTests=ON -DJSON_FastTests=ON -DJSON_TestDataDirectory=${PROJECT_BINARY_DIR}/build_offline_testdata/test_data/json_test_data
@@ -622,7 +619,7 @@ add_custom_target(ci_single_binaries
add_custom_target(ci_benchmarks
COMMAND ${CMAKE_COMMAND}
-DCMAKE_BUILD_TYPE=Release -GNinja
-S${PROJECT_SOURCE_DIR}/tests/benchmarks -B${PROJECT_BINARY_DIR}/build_benchmarks
-S${PROJECT_SOURCE_DIR}/benchmarks -B${PROJECT_BINARY_DIR}/build_benchmarks
COMMAND ${CMAKE_COMMAND} --build ${PROJECT_BINARY_DIR}/build_benchmarks --target json_benchmarks
COMMAND cd ${PROJECT_BINARY_DIR}/build_benchmarks && ./json_benchmarks
COMMENT "Run benchmarks"
+2 -2
View File
@@ -1,5 +1,5 @@
set(JSON_TEST_DATA_URL https://github.com/nlohmann/json_test_data)
set(JSON_TEST_DATA_VERSION 3.2.0)
set(JSON_TEST_DATA_VERSION 3.1.0)
include(ExternalProject)
@@ -77,7 +77,7 @@ if(CMAKE_CROSSCOMPILING)
endif()
if(NOT DEFINED LIBCPP_VERSION_OUTPUT_CACHED)
try_run(RUN_RESULT_VAR COMPILE_RESULT_VAR
"${CMAKE_BINARY_DIR}" SOURCES "${CMAKE_CURRENT_LIST_DIR}/detect_libcpp_version.cpp"
"${CMAKE_BINARY_DIR}" SOURCES "${CMAKE_SOURCE_DIR}/cmake/detect_libcpp_version.cpp"
RUN_OUTPUT_VARIABLE LIBCPP_VERSION_OUTPUT
COMPILE_OUTPUT_VARIABLE LIBCPP_VERSION_COMPILE_OUTPUT
)
+1 -1
View File
@@ -42,13 +42,13 @@ string(APPEND CONTENT [=[
],
includes = ["include"],
visibility = ["//visibility:public"],
alwayslink = True,
)
cc_library(
name = "singleheader-json",
hdrs = [
"single_include/nlohmann/json.hpp",
"single_include/nlohmann/json_view.hpp",
],
includes = ["single_include"],
visibility = ["//visibility:public"],
-77
View File
@@ -48,7 +48,6 @@ INSERT INTO searchIndex(name, type, path) VALUES ('basic_json::from_bjdata', 'Fu
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json::from_bson', 'Function', 'api/basic_json/from_bson/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json::from_cbor', 'Function', 'api/basic_json/from_cbor/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json::from_msgpack', 'Function', 'api/basic_json/from_msgpack/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json::from_bon8', 'Function', 'api/basic_json/from_bon8/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json::from_ubjson', 'Function', 'api/basic_json/from_ubjson/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json::front', 'Method', 'api/basic_json/front/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json::get', 'Method', 'api/basic_json/get/index.html');
@@ -122,80 +121,12 @@ INSERT INTO searchIndex(name, type, path) VALUES ('basic_json::to_bjdata', 'Func
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json::to_bson', 'Function', 'api/basic_json/to_bson/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json::to_cbor', 'Function', 'api/basic_json/to_cbor/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json::to_msgpack', 'Function', 'api/basic_json/to_msgpack/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json::to_bon8', 'Function', 'api/basic_json/to_bon8/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json::to_string', 'Method', 'api/basic_json/to_string/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json::to_ubjson', 'Function', 'api/basic_json/to_ubjson/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json::value', 'Method', 'api/basic_json/value/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json::value_t', 'Enum', 'api/basic_json/value_t/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json::~basic_json', 'Method', 'api/basic_json/~basic_json/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_document', 'Class', 'api/basic_json_document/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_document::basic_json_document', 'Constructor', 'api/basic_json_document/basic_json_document/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_document::accept', 'Function', 'api/basic_json_document/accept/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_document::erase', 'Method', 'api/basic_json_document/erase/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_document::insert', 'Method', 'api/basic_json_document/insert/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_document::is_discarded', 'Method', 'api/basic_json_document/is_discarded/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_document::load', 'Function', 'api/basic_json_document/load/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_document::memory_usage', 'Method', 'api/basic_json_document/memory_usage/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_document::node_count', 'Method', 'api/basic_json_document/node_count/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_document::owns_source', 'Method', 'api/basic_json_document/owns_source/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_document::parse', 'Function', 'api/basic_json_document/parse/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_document::parse_copy', 'Function', 'api/basic_json_document/parse_copy/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_document::push_back', 'Method', 'api/basic_json_document/push_back/index.html');
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INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_view::cbegin', 'Method', 'api/basic_json_view/cbegin/index.html');
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INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_view::number_format', 'Enum', 'api/basic_json_view/number_format/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_view::number_token', 'Method', 'api/basic_json_view/number_token/index.html');
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INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_view::operator<<', 'Operator', 'api/basic_json_view/operator_ltlt/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_view::operator[]', 'Operator', 'api/basic_json_view/operator[]/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_view::operator==', 'Operator', 'api/basic_json_view/operator_eq/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_view::operator!=', 'Operator', 'api/basic_json_view/operator_ne/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_view::size', 'Method', 'api/basic_json_view/size/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_view::source_offset', 'Method', 'api/basic_json_view/source_offset/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_view::type', 'Method', 'api/basic_json_view/type/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_view::type_name', 'Method', 'api/basic_json_view/type_name/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_view::value', 'Method', 'api/basic_json_view/value/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('json', 'Class', 'api/json/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('json_document', 'Class', 'api/json_document/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('json_editable_document', 'Class', 'api/json_editable_document/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('json_editable_view', 'Class', 'api/json_editable_view/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('json_view', 'Class', 'api/json_view/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('json_pointer', 'Class', 'api/json_pointer/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('json_pointer::back', 'Method', 'api/json_pointer/back/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('json_pointer::empty', 'Method', 'api/json_pointer/empty/index.html');
@@ -229,10 +160,6 @@ INSERT INTO searchIndex(name, type, path) VALUES ('operator""_json_pointer', 'Li
INSERT INTO searchIndex(name, type, path) VALUES ('operator<<', 'Operator', 'api/operator_ltlt/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('operator>>', 'Operator', 'api/operator_gtgt/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('ordered_json', 'Class', 'api/ordered_json/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('ordered_json_document', 'Class', 'api/ordered_json_document/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('ordered_json_editable_document', 'Class', 'api/ordered_json_editable_document/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('ordered_json_editable_view', 'Class', 'api/ordered_json_editable_view/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('ordered_json_view', 'Class', 'api/ordered_json_view/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('ordered_map', 'Class', 'api/ordered_map/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('std::hash<basic_json>', 'Class', 'api/basic_json/std_hash/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('std::swap<basic_json>', 'Function', 'api/basic_json/std_swap/index.html');
@@ -244,7 +171,6 @@ INSERT INTO searchIndex(name, type, path) VALUES ('Binary Formats: BJData', 'Gui
INSERT INTO searchIndex(name, type, path) VALUES ('Binary Formats: BSON', 'Guide', 'features/binary_formats/bson/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('Binary Formats: CBOR', 'Guide', 'features/binary_formats/cbor/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('Binary Formats: MessagePack', 'Guide', 'features/binary_formats/messagepack/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('Binary Formats: BON8', 'Guide', 'features/binary_formats/bon8/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('Binary Formats: UBJSON', 'Guide', 'features/binary_formats/ubjson/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('Binary Values', 'Guide', 'features/binary_values/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('Comments', 'Guide', 'features/comments/index.html');
@@ -262,7 +188,6 @@ INSERT INTO searchIndex(name, type, path) VALUES ('Iterators', 'Guide', 'feature
INSERT INTO searchIndex(name, type, path) VALUES ('JSON Merge Patch', 'Guide', 'features/merge_patch/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('JSON Patch and Diff', 'Guide', 'features/json_patch/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('JSON Pointer', 'Guide', 'features/json_pointer/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('Zero-copy JSON views', 'Guide', 'features/json_view/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('nlohmann Namespace', 'Guide', 'features/namespace/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('Types', 'Guide', 'features/types/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('Types: Number Handling', 'Guide', 'features/types/number_handling/index.html');
@@ -317,5 +242,3 @@ INSERT INTO searchIndex(name, type, path) VALUES ('NLOHMANN_JSON_SERIALIZE_ENUM'
INSERT INTO searchIndex(name, type, path) VALUES ('NLOHMANN_JSON_VERSION_MAJOR', 'Macro', 'api/macros/nlohmann_json_version_major/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('NLOHMANN_JSON_VERSION_MINOR', 'Macro', 'api/macros/nlohmann_json_version_major/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('NLOHMANN_JSON_VERSION_PATCH', 'Macro', 'api/macros/nlohmann_json_version_major/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('JSON_VIEW_NO_SIMD', 'Macro', 'api/macros/json_view_no_simd/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('JSON_VIEW_USE_SSSE3', 'Macro', 'api/macros/json_view_use_ssse3/index.html');
-1
View File
@@ -219,7 +219,6 @@ Strong exception safety: if an exception occurs, the original value stays intact
- documentation on [checked access](../../features/element_access/checked_access.md)
- [`operator[]`](operator%5B%5D.md) for unchecked access by reference
- [`value`](value.md) for access with default value
- [basic_json_view::at](../basic_json_view/at.md) - the same access on a zero-copy view
## Version history
-1
View File
@@ -58,7 +58,6 @@ Constant.
## See also
- [front](front.md) to access the first element
- [basic_json_view::back](../basic_json_view/back.md) - the same access on a zero-copy view
## Version history
-6
View File
@@ -37,12 +37,6 @@ Constant.
--8<-- "examples/begin.output"
```
## See also
- [end](end.md) - returns an iterator to one past the last element
- [basic_json_view::begin](../basic_json_view/begin.md) - the same iteration on a zero-copy view (in document order,
not sorted by key)
## Version history
- Added in version 1.0.0.
@@ -36,11 +36,6 @@ Constant.
--8<-- "examples/cbegin.output"
```
## See also
- [cend](cend.md) - returns a const iterator to one past the last element
- [basic_json_view::cbegin](../basic_json_view/cbegin.md) - the same iteration on a zero-copy view
## Version history
- Added in version 1.0.0.
@@ -18,8 +18,7 @@ ignore
: ignore tags
store
: store tagged byte strings (for bytes 0xd8..0xdb) as binary values with the tag as subtype; other tagged values are
read as if the tag were ignored. If several tags precede a byte string, only the innermost one is stored.
: store tagged values as binary container with subtype (for bytes 0xd8..0xdb)
## Examples
-5
View File
@@ -36,11 +36,6 @@ Constant.
--8<-- "examples/cend.output"
```
## See also
- [cbegin](cbegin.md) - returns a const iterator to the first element
- [basic_json_view::cend](../basic_json_view/cend.md) - the same iteration on a zero-copy view
## Version history
- Added in version 1.0.0.
@@ -111,7 +111,6 @@ Logarithmic in the size of the JSON object.
- [find](find.md) find a value in an object
- [count](count.md) returns the number of occurrences of a key
- [basic_json_view::contains](../basic_json_view/contains.md) - the same check on a zero-copy view
## Version history
-1
View File
@@ -76,7 +76,6 @@ This method always returns `0` when executed on a JSON type that is not an objec
- [find](find.md) find a value in an object
- [contains](contains.md) checks whether a key exists
- [basic_json_view::count](../basic_json_view/count.md) - the same check on a zero-copy view
## Version history
-2
View File
@@ -86,8 +86,6 @@ Binary values are serialized as an object containing two keys:
- [to_string](to_string.md) returns a string representation of a JSON value
- [operator<<](../operator_ltlt.md) serialize to stream
- [`basic_json_view::dump`](../basic_json_view/dump.md) the corresponding function of `basic_json_view`, serializing
directly from a flat index without building a `basic_json` value
- [Serialization](../../features/serialization.md) - the serialization article
## Version history
-4
View File
@@ -60,10 +60,6 @@ itself is empty which is `#!cpp false` in the case of a string.
--8<-- "examples/empty.output"
```
## See also
- [basic_json_view::empty](../basic_json_view/empty.md) - the same check on a zero-copy view
## Version history
- Added in version 1.0.0.
-5
View File
@@ -37,11 +37,6 @@ Constant.
--8<-- "examples/end.output"
```
## See also
- [begin](begin.md) - returns an iterator to the first element
- [basic_json_view::end](../basic_json_view/end.md) - the same iteration on a zero-copy view
## Version history
- Added in version 1.0.0.
-1
View File
@@ -80,7 +80,6 @@ This method always returns `end()` when executed on a JSON type that is not an o
- [count](count.md) returns the number of occurrences of a key
- [contains](contains.md) checks whether a key exists
- [basic_json_view::find](../basic_json_view/find.md) - the same lookup on a zero-copy view
## Version history
@@ -104,7 +104,6 @@ Linear in the size of the input.
- [from_msgpack](from_msgpack.md) create a JSON value from an input in MessagePack format
- [from_bson](from_bson.md) create a JSON value from an input in BSON format
- [from_ubjson](from_ubjson.md) create a JSON value from an input in UBJSON format
- [from_bon8](from_bon8.md) create a JSON value from an input in BON8 format
## Version history
@@ -1,108 +0,0 @@
# <small>nlohmann::basic_json::</small>from_bon8
```cpp
// (1)
template<typename InputType>
static basic_json from_bon8(InputType&& i,
const bool strict = true,
const bool allow_exceptions = true);
// (2)
template<typename IteratorType, typename SentinelType = IteratorType>
static basic_json from_bon8(IteratorType first, SentinelType last,
const bool strict = true,
const bool allow_exceptions = true);
```
Deserializes a given input to a JSON value using the BON8 (Binary Object Notation 8) serialization format.
1. Reads from a compatible input.
2. Reads from an iterator range, or an iterator and a sentinel of a different type (C++20 ranges support).
The exact mapping and its limitations are described on a [dedicated page](../../features/binary_formats/bon8.md).
## Template parameters
`InputType`
: A compatible input, for instance:
- an `std::istream` object
- a `FILE` pointer
- a C-style array of characters
- a pointer to a null-terminated string of single byte characters
- a container `obj` for which `begin(obj)` and `end(obj)` produce a valid pair of iterators
(as found via ADL or member functions, with semantics compatible to `std::begin` and `std::end`)
`IteratorType`
: a compatible iterator type
`SentinelType`
: defaults to `IteratorType`; may be a different type comparable to `IteratorType` via `operator!=`, for instance.
- a custom sentinel type for C++20 ranges
- `std::default_sentinel_t`, when `IteratorType` is `std::counted_iterator`
## Parameters
`i` (in)
: an input in BON8 format convertible to an input adapter
`first` (in)
: iterator to the start of the input
`last` (in)
: iterator to the end of the input, or a sentinel value that compares equal to the end iterator with `operator!=`
`strict` (in)
: whether to expect the input to be consumed until EOF (`#!cpp true` by default)
`allow_exceptions` (in)
: whether to throw exceptions in case of a parse error (optional, `#!cpp true` by default)
## Return value
deserialized JSON value; in case of a parse error and `allow_exceptions` set to `#!cpp false`, the return value will be
`value_t::discarded`. The latter can be checked with [`is_discarded`](is_discarded.md).
## Exception safety
Strong guarantee: if an exception is thrown, there are no changes in the JSON value.
## Exceptions
- Throws [parse_error.110](../../home/exceptions.md#jsonexceptionparse_error110) if the given input ends prematurely or
the end of the file was not reached when `strict` was set to true
- Throws [parse_error.112](../../home/exceptions.md#jsonexceptionparse_error112) if a parse error occurs, for instance
an invalid byte, a string that is not valid UTF-8, or an object key that is not a string
## Complexity
Linear in the size of the input.
## Examples
??? example
The example shows the deserialization of a byte vector in BON8 format to a JSON value.
```cpp
--8<-- "examples/from_bon8.cpp"
```
Output:
```json
--8<-- "examples/from_bon8.output"
```
## See also
- [to_bon8](to_bon8.md) create a BON8 serialization of a JSON value
- [from_cbor](from_cbor.md) create a JSON value from an input in CBOR format
- [from_msgpack](from_msgpack.md) create a JSON value from an input in MessagePack format
- [from_bson](from_bson.md) create a JSON value from an input in BSON format
- [from_ubjson](from_ubjson.md) create a JSON value from an input in UBJSON format
- [from_bjdata](from_bjdata.md) create a JSON value from an input in BJData format
## Version history
- Added in version 3.13.0.
@@ -104,7 +104,6 @@ Linear in the size of the input.
- [from_msgpack](from_msgpack.md) for the related MessagePack format
- [from_ubjson](from_ubjson.md) for the related UBJSON format
- [from_bjdata](from_bjdata.md) for the related BJData format
- [from_bon8](from_bon8.md) for the related BON8 format
## Version history
+2 -3
View File
@@ -80,8 +80,8 @@ Strong guarantee: if an exception is thrown, there are no changes in the JSON va
the end of the file was not reached when `strict` was set to true
- Throws [parse_error.112](../../home/exceptions.md#jsonexceptionparse_error112) if unsupported features from CBOR were
used in the given input or if the input is not valid CBOR
- Throws [parse_error.113](../../home/exceptions.md#jsonexceptionparse_error113) if a map key is not a string (keys of other
types are not supported, as JSON object keys are always strings) or a string is malformed
- Throws [parse_error.113](../../home/exceptions.md#jsonexceptionparse_error113) if a string was expected as a map key,
but not found
## Complexity
@@ -110,7 +110,6 @@ Linear in the size of the input.
- [from_bson](from_bson.md) create a JSON value from an input in BSON format
- [from_ubjson](from_ubjson.md) create a JSON value from an input in UBJSON format
- [from_bjdata](from_bjdata.md) create a JSON value from an input in BJData format
- [from_bon8](from_bon8.md) create a JSON value from an input in BON8 format
## Version history
@@ -73,8 +73,8 @@ Strong guarantee: if an exception is thrown, there are no changes in the JSON va
the end of the file was not reached when `strict` was set to true
- Throws [parse_error.112](../../home/exceptions.md#jsonexceptionparse_error112) if unsupported features from
MessagePack were used in the given input or if the input is not valid MessagePack
- Throws [parse_error.113](../../home/exceptions.md#jsonexceptionparse_error113) if a map key is not a string (keys of other
types are not supported, as JSON object keys are always strings) or a string is malformed
- Throws [parse_error.113](../../home/exceptions.md#jsonexceptionparse_error113) if a string was expected as a map key,
but not found
## Complexity
@@ -103,7 +103,6 @@ Linear in the size of the input.
- [from_bson](from_bson.md) create a JSON value from an input in BSON format
- [from_ubjson](from_ubjson.md) create a JSON value from an input in UBJSON format
- [from_bjdata](from_bjdata.md) create a JSON value from an input in BJData format
- [from_bon8](from_bon8.md) create a JSON value from an input in BON8 format
## Version history
@@ -104,7 +104,6 @@ Linear in the size of the input.
- [from_msgpack](from_msgpack.md) create a JSON value from an input in MessagePack format
- [from_bson](from_bson.md) create a JSON value from an input in BSON format
- [from_bjdata](from_bjdata.md) create a JSON value from an input in BJData format
- [from_bon8](from_bon8.md) create a JSON value from an input in BON8 format
## Version history
-1
View File
@@ -51,7 +51,6 @@ Constant.
## See also
- [back](back.md) to access the last element
- [basic_json_view::front](../basic_json_view/front.md) - the same access on a zero-copy view
## Version history
-2
View File
@@ -163,8 +163,6 @@ overload (3).
- [get_ref](get_ref.md) get a reference to the stored value
- [operator ValueType](operator_ValueType.md) get a value via implicit conversion
- [Converting values](../../features/conversions.md) - the type conversions article
- [basic_json_view::get](../basic_json_view/get.md) - the same conversion on a zero-copy view (many types are
converted without ever building a `basic_json` value)
## Version history
@@ -61,8 +61,6 @@ Constant.
## See also
- [get_ptr()](get_ptr.md) get a pointer value
- [basic_json_view::get_string](../basic_json_view/get_string.md) - the closest counterpart on a zero-copy view: a
string without a copy, but as a view rather than a reference to a value that must already exist
## Version history
@@ -21,10 +21,6 @@ This overload is chosen if:
- `ValueType` is not `basic_json`,
- `json_serializer<ValueType>` has a `from_json()` method of the form `void from_json(const basic_json&, ValueType&)`
`v` must not be `const`. Passing a `const` object is a compile-time error. For types such as arithmetic types, enums,
and C arrays, the error is a `static_assert` that names the problem. For other types, the overload is not viable, and
the compiler reports that no matching `get_to` was found.
## Template parameters
`ValueType`
@@ -67,9 +63,7 @@ Depends on the `json_serializer<ValueType>::from_json()` implementation.
- [get_ref](get_ref.md) get a reference to the stored value
- [get_ptr](get_ptr.md) get a pointer to the stored value
- [Converting values](../../features/conversions.md) - the type conversions article
- [basic_json_view::get_to](../basic_json_view/get_to.md) - the same conversion on a zero-copy view
## Version history
- Since version 3.3.0.
- Added a `static_assert` with a clear message for `const` arguments in version 3.13.0.
-2
View File
@@ -290,13 +290,11 @@ Access to the JSON value
### Binary formats
- [**from_bjdata**](from_bjdata.md) (_static_) - create a JSON value from an input in BJData format
- [**from_bon8**](from_bon8.md) (_static_) - create a JSON value from an input in BON8 format
- [**from_bson**](from_bson.md) (_static_) - create a JSON value from an input in BSON format
- [**from_cbor**](from_cbor.md) (_static_) - create a JSON value from an input in CBOR format
- [**from_msgpack**](from_msgpack.md) (_static_) - create a JSON value from an input in MessagePack format
- [**from_ubjson**](from_ubjson.md) (_static_) - create a JSON value from an input in UBJSON format
- [**to_bjdata**](to_bjdata.md) (_static_) - create a BJData serialization of a given JSON value
- [**to_bon8**](to_bon8.md) (_static_) - create a BON8 serialization of a given JSON value
- [**to_bson**](to_bson.md) (_static_) - create a BSON serialization of a given JSON value
- [**to_cbor**](to_cbor.md) (_static_) - create a CBOR serialization of a given JSON value
- [**to_msgpack**](to_msgpack.md) (_static_) - create a MessagePack serialization of a given JSON value
@@ -7,8 +7,7 @@ enum class input_format_t {
msgpack,
ubjson,
bson,
bjdata,
bon8
bjdata
};
```
@@ -32,9 +31,6 @@ bson
bjdata
: BJData (Binary JData)
bon8
: BON8 (Binary Object Notation 8)
## Examples
??? example
@@ -34,10 +34,6 @@ Constant.
--8<-- "examples/is_array.output"
```
## See also
- [basic_json_view::is_array](../basic_json_view/is_array.md) - the same check on a zero-copy view
## Version history
- Added in version 1.0.0.
@@ -34,10 +34,6 @@ Constant.
--8<-- "examples/is_binary.output"
```
## See also
- [basic_json_view::is_binary](../basic_json_view/is_binary.md) - the same check on a zero-copy view
## Version history
- Added in version 3.8.0.
@@ -34,10 +34,6 @@ Constant.
--8<-- "examples/is_boolean.output"
```
## See also
- [basic_json_view::is_boolean](../basic_json_view/is_boolean.md) - the same check on a zero-copy view
## Version history
- Added in version 1.0.0.
@@ -69,11 +69,6 @@ with `allow_exceptions` set to `#!cpp false`: a parse error then yields a discar
--8<-- "examples/is_discarded.output"
```
## See also
- [basic_json_view::is_discarded](../basic_json_view/is_discarded.md) - the corresponding check on a zero-copy view,
which is `#!cpp true` if the view refers to no value
## Version history
- Added in version 1.0.0.
@@ -34,10 +34,6 @@ Constant.
--8<-- "examples/is_null.output"
```
## See also
- [basic_json_view::is_null](../basic_json_view/is_null.md) - the same check on a zero-copy view
## Version history
- Added in version 1.0.0.
@@ -49,7 +49,6 @@ constexpr bool is_number() const noexcept
- [is_number_integer()](is_number_integer.md) check if the value is an integer or unsigned integer number
- [is_number_unsigned()](is_number_unsigned.md) check if the value is an unsigned integer number
- [is_number_float()](is_number_float.md) check if the value is a floating-point number
- [basic_json_view::is_number](../basic_json_view/is_number.md) - the same check on a zero-copy view
## Version history
@@ -40,7 +40,6 @@ Constant.
- [is_number()](is_number.md) check if the value is a number
- [is_number_integer()](is_number_integer.md) check if the value is an integer or unsigned integer number
- [is_number_unsigned()](is_number_unsigned.md) check if the value is an unsigned integer number
- [basic_json_view::is_number_float](../basic_json_view/is_number_float.md) - the same check on a zero-copy view
## Version history
@@ -40,7 +40,6 @@ Constant.
- [is_number()](is_number.md) check if the value is a number
- [is_number_unsigned()](is_number_unsigned.md) check if the value is an unsigned integer number
- [is_number_float()](is_number_float.md) check if the value is a floating-point number
- [basic_json_view::is_number_integer](../basic_json_view/is_number_integer.md) - the same check on a zero-copy view
## Version history
@@ -40,7 +40,6 @@ Constant.
- [is_number()](is_number.md) check if the value is a number
- [is_number_integer()](is_number_integer.md) check if the value is an integer or unsigned integer number
- [is_number_float()](is_number_float.md) check if the value is a floating-point number
- [basic_json_view::is_number_unsigned](../basic_json_view/is_number_unsigned.md) - the same check on a zero-copy view
## Version history
@@ -34,10 +34,6 @@ Constant.
--8<-- "examples/is_object.output"
```
## See also
- [basic_json_view::is_object](../basic_json_view/is_object.md) - the same check on a zero-copy view
## Version history
- Added in version 1.0.0.
@@ -62,7 +62,6 @@ This library extends primitive types to binary types, because binary types are r
- [is_boolean()](is_boolean.md) returns whether the JSON value is a boolean
- [is_number()](is_number.md) returns whether the JSON value is a number
- [is_binary()](is_binary.md) returns whether the JSON value is a binary array
- [basic_json_view::is_primitive](../basic_json_view/is_primitive.md) - the same check on a zero-copy view
## Version history
@@ -34,10 +34,6 @@ Constant.
--8<-- "examples/is_string.output"
```
## See also
- [basic_json_view::is_string](../basic_json_view/is_string.md) - the same check on a zero-copy view
## Version history
- Added in version 1.0.0.
@@ -57,7 +57,6 @@ Note that though strings are containers in C++, they are treated as primitive va
- [is_primitive()](is_primitive.md) returns whether JSON value is primitive
- [is_array()](is_array.md) returns whether the value is an array
- [is_object()](is_object.md) returns whether the value is an object
- [basic_json_view::is_structured](../basic_json_view/is_structured.md) - the same check on a zero-copy view
## Version history
-2
View File
@@ -99,8 +99,6 @@ When iterating over an array, `key()` will return the index of the element as st
- [begin](begin.md) returns an iterator to the first element
- [end](end.md) returns an iterator to one past the last element
- [basic_json_view::items](../basic_json_view/items.md) - the same range on a zero-copy view (`#!cpp const auto`,
not `#!cpp const auto&`: items are produced on the fly)
## Version history
@@ -254,8 +254,6 @@ Strong exception safety: if an exception occurs, the original value stays intact
- documentation on [runtime assertions](../../features/assertions.md)
- see [`at`](at.md) for access by reference with range checking
- see [`value`](value.md) for access with default value
- [basic_json_view::operator[]](../basic_json_view/operator%5B%5D.md) - the same access on a zero-copy view (always
returns a discarded view instead of assuming undefined behavior)
## Version history
@@ -166,8 +166,6 @@ Linear.
- [operator!=](operator_ne.md) compare for inequality
- [operator<=>](operator_spaceship.md) comparison: 3-way (C++20)
- [basic_json_view::operator==](../basic_json_view/operator_eq.md) - the same comparison on a zero-copy view, without
building a `basic_json` value for it
## Version history
@@ -89,12 +89,6 @@ Linear.
--8<-- "examples/operator__notequal__nullptr_t.output"
```
## See also
- [operator==](operator_eq.md) compare for equality
- [basic_json_view::operator!=](../basic_json_view/operator_ne.md) - the same comparison on a zero-copy view, without
building a `basic_json` value for it
## Version history
1. Added in version 1.0.0. Added C++20 member functions in version 3.11.0. Changed in version 3.13.0 to remove
@@ -5,7 +5,7 @@ class parse_error : public exception;
```
The library throws this exception when a parse error occurs. Parse errors can occur during the deserialization of
JSON text, BJData, BON8, BSON, CBOR, MessagePack, UBJSON, as well as when using JSON Patch.
JSON text, BSON, CBOR, MessagePack, UBJSON, as well as when using JSON Patch.
Member `byte` holds the byte index of the last read character in the input file (see note below).
+2 -7
View File
@@ -65,14 +65,11 @@ The SAX event lister must follow the interface of [`json_sax`](../json_sax/index
: SAX event listener (must not be null)
`format` (in)
: the format to parse (JSON, BJData, BON8, BSON, CBOR, MessagePack, or UBJSON) (optional, `input_format_t::json` by
default), see
: the format to parse (JSON, CBOR, MessagePack, or UBJSON) (optional, `input_format_t::json` by default), see
[`input_format_t`](input_format_t.md) for more information
`strict` (in)
: whether the input has to be consumed completely (optional, `#!cpp true` by default); when `#!cpp false` and the
input is a `#!cpp std::istream`, the character that terminates a number is consumed unless
[`JSON_PRECISE_STREAM_POSITION`](../macros/json_precise_stream_position.md) is defined to `1`; see [`operator>>`](../operator_gtgt.md#notes)
: whether the input has to be consumed completely (optional, `#!cpp true` by default)
`ignore_comments` (in)
: whether comments should be ignored and treated like whitespace (`#!cpp true`) or yield a parse error
@@ -139,8 +136,6 @@ A UTF-8 byte order mark is silently ignored.
- Added `ignore_trailing_commas` in version 3.13.0.
- Extended container support (1) to include types with lvalue-only ADL `begin`/`end` (matching `std::begin`/`std::end` semantics) in version 3.13.0.
- Extended overload (2) to accept heterogeneous iterator+sentinel pairs (C++20 ranges support) in version 3.13.0.
- `JSON_PRECISE_STREAM_POSITION` added in version 3.13.0 to optionally leave a `#!cpp std::istream` positioned right
after the parsed value when `strict` is `#!cpp false`.
!!! warning "Deprecation"
-4
View File
@@ -51,10 +51,6 @@ JSON value which is `1` in the case of a string.
--8<-- "examples/size.output"
```
## See also
- [basic_json_view::size](../basic_json_view/size.md) - the same function on a zero-copy view
## Version history
- Added in version 1.0.0.
@@ -84,7 +84,6 @@ Linear in the size of the JSON value `j`.
- [to_msgpack](to_msgpack.md) create a MessagePack serialization of a JSON value
- [to_bson](to_bson.md) create a BSON serialization of a JSON value
- [to_ubjson](to_ubjson.md) create a UBJSON serialization of a JSON value
- [to_bon8](to_bon8.md) create a BON8 serialization of a JSON value
## Version history
@@ -1,76 +0,0 @@
# <small>nlohmann::basic_json::</small>to_bon8
```cpp
// (1)
static std::vector<std::uint8_t> to_bon8(const basic_json& j);
// (2)
static void to_bon8(const basic_json& j, detail::output_adapter<std::uint8_t> o);
static void to_bon8(const basic_json& j, detail::output_adapter<char> o);
```
Serializes a given JSON value `j` to a byte vector using the BON8 (Binary Object Notation 8) serialization format. BON8
is a compact binary serialization format that stores strings as UTF-8 without a length prefix.
1. Returns a byte vector containing the BON8 serialization.
2. Writes the BON8 serialization to an output adapter.
The exact mapping and its limitations are described on a [dedicated page](../../features/binary_formats/bon8.md).
## Parameters
`j` (in)
: JSON value to serialize
`o` (in)
: output adapter to write serialization to
## Return value
1. BON8 serialization as a byte vector
2. (none)
## Exception safety
Strong guarantee: if an exception is thrown, there are no changes in the JSON value `j`, which is never modified.
With (2), the bytes written before the exception remain in the output adapter.
## Exceptions
- Throws [out_of_range.407](../../home/exceptions.md#jsonexceptionout_of_range407) if `j` contains an unsigned integer
above 9223372036854775807, which BON8 cannot represent
- Throws [type_error.316](../../home/exceptions.md#jsonexceptiontype_error316) if `j` contains a string that is not
valid UTF-8
## Complexity
Linear in the size of the JSON value `j`.
## Examples
??? example
The example shows the serialization of a JSON value to a byte vector in BON8 format.
```cpp
--8<-- "examples/to_bon8.cpp"
```
Output:
```json
--8<-- "examples/to_bon8.output"
```
## See also
- [from_bon8](from_bon8.md) create a JSON value from an input in BON8 format
- [to_cbor](to_cbor.md) create a CBOR serialization of a JSON value
- [to_msgpack](to_msgpack.md) create a MessagePack serialization of a JSON value
- [to_bson](to_bson.md) create a BSON serialization of a JSON value
- [to_ubjson](to_ubjson.md) create a UBJSON serialization of a JSON value
- [to_bjdata](to_bjdata.md) create a BJData serialization of a JSON value
## Version history
- Added in version 3.13.0.
+3 -4
View File
@@ -46,8 +46,9 @@ Strong guarantee: if an exception is thrown, there are no changes in the JSON va
## Complexity
Linear in the size of the JSON value `j`. The length prefixes of all nested documents and arrays are computed in one
pass before anything is written.
Proportional to the size of the JSON value `j` multiplied by its maximum nesting
depth, `O(n × d)`. BSON length prefixes are computed recursively before nested
values are written.
## Examples
@@ -72,9 +73,7 @@ pass before anything is written.
- [to_msgpack](to_msgpack.md) create a MessagePack serialization of a JSON value
- [to_ubjson](to_ubjson.md) create a UBJSON serialization of a JSON value
- [to_bjdata](to_bjdata.md) create a BJData serialization of a JSON value
- [to_bon8](to_bon8.md) create a BON8 serialization of a JSON value
## Version history
- Added in version 3.4.0.
- Linear in the size of `j`, and no longer limited by the call stack for deeply nested values, since version 3.13.0.
@@ -62,7 +62,6 @@ Linear in the size of the JSON value `j`.
- [to_bson](to_bson.md) create a BSON serialization of a JSON value
- [to_ubjson](to_ubjson.md) create a UBJSON serialization of a JSON value
- [to_bjdata](to_bjdata.md) create a BJData serialization of a JSON value
- [to_bon8](to_bon8.md) create a BON8 serialization of a JSON value
## Version history
@@ -34,15 +34,6 @@ The exact mapping and its limitations are described on a [dedicated page](../../
Strong guarantee: if an exception is thrown, there are no changes in the JSON value.
## Exceptions
- Throws [`out_of_range.412`](../../home/exceptions.md#jsonexceptionout_of_range412) if the length of a string, binary
value, array, or object exceeds 4294967295, the maximum MessagePack can store; example:
`"MessagePack length 4294967296 exceeds maximum of 4294967295"`
- Throws [`out_of_range.415`](../../home/exceptions.md#jsonexceptionout_of_range415) if the subtype of a binary value
exceeds 255, the maximum of the MessagePack ext type; example:
`"subtype 70000 is too large for the MessagePack ext type (max 255)"`
## Complexity
Linear in the size of the JSON value `j`.
@@ -70,9 +61,7 @@ Linear in the size of the JSON value `j`.
- [to_bson](to_bson.md) create a BSON serialization of a JSON value
- [to_ubjson](to_ubjson.md) create a UBJSON serialization of a JSON value
- [to_bjdata](to_bjdata.md) create a BJData serialization of a JSON value
- [to_bon8](to_bon8.md) create a BON8 serialization of a JSON value
## Version history
- Added in version 2.0.9.
- Throws `out_of_range.412` and `out_of_range.415` since version 3.13.0.
@@ -77,7 +77,6 @@ Linear in the size of the JSON value `j`.
- [to_msgpack](to_msgpack.md) create a MessagePack serialization of a JSON value
- [to_bson](to_bson.md) create a BSON serialization of a JSON value
- [to_bjdata](to_bjdata.md) create a BJData serialization of a JSON value
- [to_bon8](to_bon8.md) create a BON8 serialization of a JSON value
## Version history
-4
View File
@@ -47,10 +47,6 @@ Constant.
--8<-- "examples/type.output"
```
## See also
- [basic_json_view::type](../basic_json_view/type.md) - the same function on a zero-copy view
## Version history
- Added in version 1.0.0.
@@ -52,11 +52,6 @@ Constant.
--8<-- "examples/type_name.output"
```
## See also
- [type](type.md) - return the type of the JSON value
- [basic_json_view::type_name](../basic_json_view/type_name.md) - the same function on a zero-copy view
## Version history
- Added in version 1.0.0.
-1
View File
@@ -181,7 +181,6 @@ changes to any JSON value.
- see [`at`](at.md) for access by reference with range checking
- see [`operator[]`](operator%5B%5D.md) for unchecked access by reference
- [basic_json_view::value](../basic_json_view/value.md) - the same access on a zero-copy view
## Version history
@@ -1,67 +0,0 @@
# <small>nlohmann::basic_json_document::</small>accept
```cpp
template<typename InputType>
static bool accept(InputType&& input,
const bool ignore_comments = false,
const bool ignore_trailing_commas = false);
```
Checks whether the input is valid JSON, accepting and rejecting exactly what
[`BasicJsonType::accept()`](../basic_json/accept.md) does, with the same options. Unlike [`parse()`](parse.md), this
function never throws an exception for invalid input, and the returned `#!cpp bool` is the only result -- no document
is returned.
## Template parameters
`InputType`
: A compatible input; see [`parse`](parse.md#template-parameters).
## Parameters
`input` (in)
: Input to check.
`ignore_comments` (in)
: whether comments should be ignored and treated like whitespace (`#!cpp true`) or yield a parse error
(`#!cpp false`); (optional, `#!cpp false` by default)
`ignore_trailing_commas` (in)
: whether trailing commas in arrays or objects should be ignored and treated like whitespace (`#!cpp true`) or
yield a parse error (`#!cpp false`); (optional, `#!cpp false` by default)
## Return value
Whether the input is valid JSON.
## Exception safety
Strong guarantee: this function itself never throws for an invalid input; it can only throw what allocating the
input's own copy (for inputs that are always read into a buffer) throws.
## Complexity
Linear in the length of the input.
## Examples
??? example
```cpp
--8<-- "examples/basic_json_document__accept.cpp"
```
Output:
```json
--8<-- "examples/basic_json_document__accept.output"
```
## See also
- [parse](parse.md) - deserialize from a compatible input
- [`BasicJsonType::accept`](../basic_json/accept.md) - the corresponding function of `basic_json`
## Version history
- Added in version 3.13.0.
@@ -1,58 +0,0 @@
# <small>nlohmann::basic_json_document::</small>basic_json_document
```cpp
// (1)
basic_json_document() = default;
// (2)
basic_json_document(basic_json_document&& other) noexcept = default;
// (3)
basic_json_document(const basic_json_document&) = delete;
```
1. Creates an empty (discarded) document: [`root()`](root.md) returns a discarded view, and
[`is_discarded()`](is_discarded.md) is `#!cpp true`.
2. Move constructor. Takes over `other`'s index and, if owned, its text; `other` is left as an empty document. Views
taken from `other` before the move remain valid, because the index is heap-allocated independently of the
`basic_json_document` object.
3. `basic_json_document` is move-only. Copying is disabled because it would either duplicate a potentially large index
and text, or leave two documents claiming to borrow the same buffer.
## Parameters
`other` (in)
: another document to move the index and text from
## Exception safety
No-throw guarantee: the default and move constructors never throw exceptions.
## Complexity
Constant, for the default and move constructors.
## Examples
??? example
The example below shows the default constructor and demonstrates that `basic_json_document` is move-only.
```cpp
--8<-- "examples/basic_json_document__basic_json_document.cpp"
```
Output:
```json
--8<-- "examples/basic_json_document__basic_json_document.output"
```
## See also
- [parse](parse.md) - deserialize from a compatible input
- [is_discarded](is_discarded.md) - return whether the last parse failed
## Version history
- Added in version 3.13.0.
@@ -1,128 +0,0 @@
# <small>nlohmann::basic_json_document::</small>erase
```cpp
// (1)
std::size_t erase(view_type object, string_view_t key);
// (2)
template<typename I>
void erase(view_type array, I idx);
// (3)
std::size_t erase(const json_pointer& ptr);
```
Only an **editable** document (`#!cpp Editable == true`, e.g. [`json_editable_document`](../json_editable_document.md))
has `erase`; calling it on a read-only `basic_json_document` fails to compile (`#!cpp static_assert`).
1. Removes every member of `object` whose key is `key` (see [Notes](#notes) on duplicate keys) and returns how many
were removed; `#!cpp 0` if `object` has no member with this key.
2. Removes the element at index `idx` of `array`, which must already exist (`#!cpp idx < array.size()`).
3. Removes the value the JSON pointer `ptr` refers to, relative to [`root()`](root.md), and returns how many values
were removed: the *parent* of the target must already exist, and the target itself is removed as in 1. (an object
member; `#!cpp 0` or more) or 2. (an array element; always `#!cpp 1`). `ptr` must not be empty -- [`root()`](root.md)
itself cannot be erased.
## Template parameters
`I`
: an integral type other than `#!cpp bool`, deduced (overloads taking a `#!cpp bool` or a non-integral type for
`idx` do not participate in overload resolution).
## Parameters
`object` (in)
: the object to remove a member of
`array` (in)
: the array to remove an element of
`key` (in)
: the key of the member(s) to remove
`idx` (in)
: the index of the element to remove; a negative value throws (see [Exceptions](#exceptions))
`ptr` (in)
: a JSON pointer to the value to remove, relative to `root()`
## Return value
1. the number of removed members (`#!cpp 0` if `object` had none with this `key`)
2. (nothing)
3. the number of removed values (`#!cpp 0` or more for an object member, always `#!cpp 1` for an array element)
## Exceptions
1. Throws [`type_error.307`](../../home/exceptions.md#jsonexceptiontype_error307) if `object` is not an object -- the
same message [`BasicJsonType::erase`](../basic_json/erase.md) throws for the same type.
2. Throws `type_error.307` if `array` is not an array. Throws
[`out_of_range.401`](../../home/exceptions.md#jsonexceptionout_of_range401) if `idx` is negative, or if
`#!cpp idx >= array.size()`.
3. Throws [`out_of_range.405`](../../home/exceptions.md#jsonexceptionout_of_range405) ("JSON pointer has no parent")
if `ptr` is empty. Throws what [`at`](../basic_json_view/at.md) throws (overload 3) for resolving `ptr`'s parent.
For the last reference token itself: if the parent is an array, throws what 2. throws for an index that is out of
range, or, for a token that is not a valid array index,
[`parse_error.106`](../../home/exceptions.md#jsonexceptionparse_error106) (a leading `#!cpp '0'`),
[`parse_error.109`](../../home/exceptions.md#jsonexceptionparse_error109) (not a number),
[`out_of_range.410`](../../home/exceptions.md#jsonexceptionout_of_range410) (too large for `size_type`), or
[`out_of_range.404`](../../home/exceptions.md#jsonexceptionout_of_range404) (an empty token); otherwise (an
object, or a primitive value the pointer's parent resolves to) throws what 1. throws.
Every overload also throws [`invalid_iterator.202`](../../home/exceptions.md#jsonexceptioninvalid_iterator202) ("view
does not belong to this document") if `object`/`array` is a [discarded](../basic_json_view/is_discarded.md) view or a
view of a *different* document (overloads 1-2 only; overload 3 always starts from this document's own
[`root()`](root.md)).
## Complexity
1. Linear in the number of members of `object`.
2. Linear in the number of elements of `array` at or after `idx` (they move one slot over).
3. Linear in the number of reference tokens of `ptr` and, for each token, in the number of members of the object at
that level or the index into the array (as [`at`](../basic_json_view/at.md)), plus the complexity of 1. or 2. for
the last token.
## Notes
!!! info "Duplicate keys"
Overload 1. removes *every* member with `key`, not just the first -- unlike [`set`](set.md), which assigns the
first occurrence and drops the rest. This is why it returns a count rather than a single view: there may be
more than one member removed, or none.
Like [`set`](set.md) and [`push_back`](push_back.md), `erase` never moves an element's *value*: a view still
referring to a removed member or element keeps showing what it last held (see [Edits](index.md#edits)) -- it just no
longer appears when `array`/`object` is read, dumped, or iterated. Removing an element of `array` (2.) does shift the
*links* to the elements after it, the same way `insert`, `set`, or `push_back` on the same array would; any iterator
already taken over `array`/`object` is invalidated by an erase, since it was walking the old layout.
## Examples
??? example
The example below drops a deprecated field and a decommissioned entry from a configuration document -- using all
three overloads -- and shows what stays intact that would not with a plain `json`/`ordered_json` value: the order
of the fields around the ones removed, and the exact spelling of a number that was never touched.
```cpp
--8<-- "examples/basic_json_document__erase.cpp"
```
Output:
```json
--8<-- "examples/basic_json_document__erase.output"
```
## See also
- [insert](insert.md) - insert an element into an array
- [set](set.md) - replace a value, or set an object member, an array element, or the value a JSON pointer refers to
- [push_back](push_back.md) - append to an array
- [root](root.md) - the view of the root value, the starting point of overload 3
- [`BasicJsonType::erase`](../basic_json/erase.md) - the corresponding function of `basic_json`
- [Edits](index.md#edits) - what an edit guarantees, for every overload
## Version history
- Added in version 3.13.0.
@@ -1,118 +0,0 @@
# <small>nlohmann::</small>basic_json_document
<small>Defined in header `<nlohmann/json_view.hpp>`</small>
```cpp
template<typename BasicJsonType, bool Editable = false>
class basic_json_document;
```
A parsed JSON text, held as a flat index of its values
([16 bytes per value](../../home/architecture.md#node-index-of-json-views)) instead of a tree of `BasicJsonType` values.
Strings and numbers stay in the source text; only strings that contain escapes are decoded, into one buffer owned by
the document. [`basic_json_view`](../basic_json_view/index.md) is a read-only handle to one value of a
`basic_json_document`; [`materialize()`](../basic_json_view/materialize.md) turns a subtree back into the
`BasicJsonType` value that [`BasicJsonType::parse()`](../basic_json/parse.md) would have produced for it.
A document may **borrow** the text it was parsed from (the caller's buffer must then outlive the document) or **own**
it (a copy, or an rvalue `#!cpp std::string` that was moved in); see [`owns_source`](owns_source.md). `basic_json_document`
is move-only: copying a document would either duplicate a potentially large index and text, or leave two documents
claiming to borrow the same buffer, so it is disabled.
With `#!cpp Editable == true`, the document also offers [`set`](set.md), [`push_back`](push_back.md),
[`insert`](insert.md), and [`erase`](erase.md) to change values in place, see [Edits](#edits) below. The source text
itself is never written; a read-only document (`#!cpp Editable == false`, the default) does not carry any of the
bookkeeping edits need, and calling any of them on one fails to compile (`#!cpp static_assert`).
## Template parameters
`BasicJsonType`
: a specialization of [`basic_json`](../basic_json/index.md), for instance [`json`](../json.md) or
[`ordered_json`](../ordered_json.md). Only 64-bit `number_integer_t`/`number_unsigned_t` types are supported; this
is checked with a `static_assert`.
`Editable`
: whether the document supports [`set`](set.md), [`push_back`](push_back.md), [`insert`](insert.md), and
[`erase`](erase.md) (optional, `#!cpp false` by default). See [Edits](#edits) below.
## Specializations
- [**json_document**](../json_document.md) - read-only documents of the default specialization [`json`](../json.md)
- [**ordered_json_document**](../ordered_json_document.md) - read-only documents of
[`ordered_json`](../ordered_json.md)
- [**json_editable_document**](../json_editable_document.md) - editable documents of [`json`](../json.md)
- [**ordered_json_editable_document**](../ordered_json_editable_document.md) - editable documents of
[`ordered_json`](../ordered_json.md)
## Member types
- **view_type** - the type of view returned by [`root()`](root.md) (`#!cpp basic_json_view<BasicJsonType, Editable>`)
- **value_t** - the JSON type enumeration, see [`basic_json::value_t`](../basic_json/value_t.md)
## Member functions
- [(constructor)](basic_json_document.md)
### Parsing
- [**parse**](parse.md) (_static_) - deserialize from a compatible input, borrowing or owning it as appropriate
- [**parse_copy**](parse_copy.md) (_static_) - deserialize a copy of a compatible input
- [**accept**](accept.md) (_static_) - check whether the input is valid JSON
- [**read**](read.md) - (re-)parse into this document, reusing its memory
### Access
- [**root**](root.md) - the view of the root value
- [**is_discarded**](is_discarded.md) - return whether the last parse failed
- [**source**](source.md) - the parsed text
- [**owns_source**](owns_source.md) - return whether the document holds its own copy of the text
- [**node_count**](node_count.md) - the number of index entries (values plus object keys)
- [**memory_usage**](memory_usage.md) - the number of bytes held by the document
- [**shrink_to_fit**](shrink_to_fit.md) - release unused index capacity
### Images
- [**save**](save.md) - the document as an image that `load()` reads without parsing
- [**load**](load.md) (_static_) - read an image written by `save()`
### Edits
- [**set**](set.md) - replace a value, or set an object member, an array element, or the value a JSON pointer refers
to (`#!cpp Editable` documents only)
- [**push_back**](push_back.md) - append to an array (`#!cpp Editable` documents only)
- [**insert**](insert.md) - insert an element into an array before a given position (`#!cpp Editable` documents only)
- [**erase**](erase.md) - remove an object member, an array element, or the value a JSON pointer refers to
(`#!cpp Editable` documents only)
## Edits
An editable document (`#!cpp Editable == true`) can be changed after parsing, with [`set`](set.md),
[`push_back`](push_back.md), [`insert`](insert.md), and [`erase`](erase.md);
[`json_editable_document`](../json_editable_document.md) and
[`ordered_json_editable_document`](../ordered_json_editable_document.md) are the corresponding specializations. A few
points apply to every edit:
- **The source text is never written**, and the parsed index never moves: every value keeps the node it was parsed
into, so [views](../basic_json_view/index.md) taken before an edit stay valid, including
[`root()`](root.md). New values (and the element sequences of an edited array/object) go to storage owned by the
document, allocated on demand.
- **A view keeps referring to the same value.** After [`set`](set.md) replaces the value a view refers to, that view
sees the new value; a view of a value that a later edit replaces or drops keeps showing what it last held. An edit
of an array or object, however, **invalidates the iterators taken over it** (its members may now live in a
different sequence), and a string obtained with [`get_string()`](../basic_json_view/get_string.md) stays valid even
as further edits happen (earlier buffers of edited text are kept alive, not overwritten).
- **Values are accepted three ways:** a [`basic_json_view`](../basic_json_view/index.md) of *any* document
(read-only or editable; it is copied, nothing is shared with the source document), a `BasicJsonType` value, or
anything `BasicJsonType` can be constructed from (numbers, strings, `#!cpp bool`, `#!cpp nullptr`, containers, ...).
- [`dump()`](../basic_json_view/dump.md) writes an edited document with members in document order, new members at
the end, and, with [`number_format::source`](../basic_json_view/number_format.md), keeps the spelling of every
number that was not itself edited -- see [Editing a document](../../features/json_view.md#editing-a-document) for
why this matters.
- [`read()`](read.md) discards all edits, [`shrink_to_fit()`](shrink_to_fit.md) does not move the node index once
there are edits, and [`memory_usage()`](memory_usage.md) includes the memory edits use.
[`source_offset()`](../basic_json_view/source_offset.md) of a value introduced by an edit is
`#!cpp static_cast<std::size_t>(-1)`, the same value it reports for a decoded string.
## Version history
- Added in version 3.13.0.
@@ -1,114 +0,0 @@
# <small>nlohmann::basic_json_document::</small>insert
```cpp
template<typename I, typename V>
view_type insert(view_type array, I idx, V&& value);
```
Only an **editable** document (`#!cpp Editable == true`, e.g. [`json_editable_document`](../json_editable_document.md))
has `insert`; calling it on a read-only `basic_json_document` fails to compile (`#!cpp static_assert`).
Inserts `value` into `array` as a new element before position `idx`, which must not be past the end
(`#!cpp idx <= array.size()`; `#!cpp idx == array.size()` appends, like [`push_back`](push_back.md)). Unlike
[`push_back`](push_back.md), a [null](../basic_json_view/is_null.md) `array` does *not* first become an empty array:
`array` must already be an array.
`value` is accepted three ways: a [`basic_json_view`](../basic_json_view/index.md) of *any* document -- read-only or
editable, and it does not have to be `array`'s own document -- which is copied so that nothing is shared with the
source document afterward; a `BasicJsonType` value; or anything `BasicJsonType` can be constructed from (numbers,
strings, `#!cpp bool`, `#!cpp nullptr`, containers, ...).
## Template parameters
`I`
: an integral type other than `#!cpp bool`, deduced (overloads taking a `#!cpp bool` or a non-integral type for
`idx` do not participate in overload resolution).
`V`
: the type of `value`, deduced; see above for what is accepted.
## Parameters
`array` (in)
: the array to insert into
`idx` (in)
: the position to insert `value` before; a negative value throws (see [Exceptions](#exceptions))
`value` (in)
: the value to insert
## Return value
a view of the new element, now holding `value`
## Exception safety
Basic exception safety: `value` is fully encoded -- including the checks below -- into storage owned by the document
before anything already reachable from [`root()`](root.md) is touched, so a failure while encoding `value` (an
invalid argument, or `#!cpp std::bad_alloc`) leaves the document completely unchanged, other than memory allocated
for the encoding that is not reclaimed. A failure of a later allocation -- while `array` switches from its parsed
layout to a growable block, or while that block grows, see [Notes](#notes) -- can still leave `array` already
switched to that layout even though `value` itself was not inserted.
## Exceptions
Throws [`type_error.309`](../../home/exceptions.md#jsonexceptiontype_error309) if `array` is not an array -- the same
message [`BasicJsonType::insert`](../basic_json/insert.md) throws for the same type; a null `array` throws this too
(see above). Throws [`out_of_range.401`](../../home/exceptions.md#jsonexceptionout_of_range401) if `idx` is negative,
or if `#!cpp idx > array.size()`. Throws
[`invalid_iterator.202`](../../home/exceptions.md#jsonexceptioninvalid_iterator202) ("view does not belong to this
document") if `array` is a [discarded](../basic_json_view/is_discarded.md) view or a view of a *different* document.
Throws [`type_error.302`](../../home/exceptions.md#jsonexceptiontype_error302) if `value` is a
[discarded](../basic_json_view/is_discarded.md) view or a [discarded](../basic_json/is_discarded.md) `BasicJsonType`
value, and [`type_error.319`](../../home/exceptions.md#jsonexceptiontype_error319) if `value` is (or contains) a
binary value -- `BasicJsonType` can hold one, but a `json_document` cannot. Throws
[`type_error.316`](../../home/exceptions.md#jsonexceptiontype_error316) if `value` is (or contains) a string that is
not valid UTF-8, with the same message [`BasicJsonType::dump()`](../basic_json/dump.md) gives for that string.
## Complexity
Linear in the number of elements of `array` at or after `idx` (they move one slot over), plus time linear in the
size of `value` to encode it into the document's storage (constant for a scalar, linear in the number of nested
values for an array or object): like [`push_back`](push_back.md), the elements of `array` move to a growable block
of links the first time it is inserted into (or [`set`](set.md)/[`push_back`](push_back.md) on), and that block
grows in amortized constant time; inserting before the end within that block still shifts every later element.
## Notes
Like [`set`](set.md) on a member or an element, `insert` never moves an existing *element's value* -- only where
`array`'s *links* to its elements live -- so a view of an existing element of `array` stays valid across an
`insert`, and keeps referring to the same element even though its index shifts. Any iterator already taken over
`array` is invalidated, since it was walking the old layout. See [Edits](index.md#edits) for what stays valid across
an edit in general.
## Examples
??? example
The example below inserts a step into the middle of a deployment plan, without touching the steps that come
after it, and shows that a view taken before the insert keeps referring to the same element even though its
index shifts -- something a plain `json`/`ordered_json` array, or its `std::vector`-based storage, has no
equivalent for.
```cpp
--8<-- "examples/basic_json_document__insert.cpp"
```
Output:
```json
--8<-- "examples/basic_json_document__insert.output"
```
## See also
- [push_back](push_back.md) - append to an array
- [erase](erase.md) - remove an object member, an array element, or the value a JSON pointer refers to
- [set](set.md) - replace a value, or set an object member, an array element, or the value a JSON pointer refers to
- [`BasicJsonType::insert`](../basic_json/insert.md) - the corresponding function of `basic_json`
- [Edits](index.md#edits) - what an edit guarantees, for every overload
## Version history
- Added in version 3.13.0.
@@ -1,49 +0,0 @@
# <small>nlohmann::basic_json_document::</small>is_discarded
```cpp
bool is_discarded() const noexcept;
```
Returns whether the document holds no value, either because it was default-constructed or because the last call to
[`parse()`](parse.md), [`parse_copy()`](parse_copy.md), or [`read()`](read.md) failed with `allow_exceptions` set to
`#!cpp false`.
## Return value
`#!cpp true` if the document is discarded, `#!cpp false` otherwise.
## Exception safety
No-throw guarantee: this function never throws exceptions.
## Complexity
Constant.
## Notes
When the document is discarded, [`root()`](root.md) returns a discarded view (its
[`is_discarded()`](../basic_json_view/is_discarded.md) is also `#!cpp true`).
## Examples
??? example
```cpp
--8<-- "examples/basic_json_document__is_discarded.cpp"
```
Output:
```json
--8<-- "examples/basic_json_document__is_discarded.output"
```
## See also
- [parse](parse.md) - deserialize from a compatible input
- [is_discarded (basic_json_view)](../basic_json_view/is_discarded.md) - return whether a view is invalid
## Version history
- Added in version 3.13.0.
@@ -1,169 +0,0 @@
# <small>nlohmann::basic_json_document::</small>load
```cpp
// (1)
static basic_json_document load(const std::uint8_t* image, std::size_t size,
const image_check check = image_check::full);
// (2)
static basic_json_document load(const std::vector<std::uint8_t>& image,
const image_check check = image_check::full);
// (3)
static basic_json_document load(std::vector<std::uint8_t>&& image,
const image_check check = image_check::full);
```
1. Reads an image [`save()`](save.md) wrote, from a pointer and a byte count. The image is **borrowed**: `image`
must stay alive and unchanged for as long as the returned document, and any view taken from it, is used.
2. Reads an image from a `#!cpp std::vector`. Also **borrowed** -- equivalent to overload 1 called with
`#!cpp image.data()` and `#!cpp image.size()`.
3. Reads an image, keeping the vector instead of copying it: `image` is moved into the document (no copy), which
then owns it for as long as it needs the text and the decoded strings. [`owns_source()`](owns_source.md) is
`#!cpp true` afterward.
In every overload, the node index is copied into storage the document itself owns -- so that it is properly aligned,
and, for an [editable](index.md#edits) document, can be edited -- while the text and the decoded strings stay in
`image`. The hash indexes [large objects](../../features/json_view.md) use for lookup are rebuilt, exactly as after
parsing.
## Parameters
`image` (in)
: the image [`save()`](save.md) wrote (overloads 1 and 2), or one to take ownership of (overload 3)
`size` (in)
: the number of bytes at `image` (overload 1)
`check` (in)
: how thoroughly to validate `image` before trusting it; see [`image_check`](#image_check) below (optional,
`#!cpp image_check::full` by default)
## Return value
The document read from the image.
## Exception safety
Overloads 1 and 2 give the strong guarantee: `image` is only read, never written, so a thrown exception leaves the
caller's buffer untouched.
Overload 3 moves `image` into the document *before* validating it, so that a good image is kept without a copy. If
loading then fails, the partially built document -- and the vector now inside it -- is discarded along with the
exception, and `image` itself is left **empty**, not restored to what was passed in. Move a copy in instead, or
validate with overload 2 first, if the original vector must survive a failed load.
## Exceptions
On a big-endian target, throws [`type_error.320`](../../home/exceptions.md#jsonexceptiontype_error320) -- the same
exception [`save()`](save.md#exceptions) throws there, since the image format is little-endian only.
Otherwise throws [`parse_error.116`](../../home/exceptions.md#jsonexceptionparse_error116) if `image` is not one
`save()` could have written, or fails the requested `check`:
| message | when |
|------------------------|------------------------------------------------------------------------------------------------------|
| `too short` | `image` is `#!cpp nullptr`, or `size` is smaller than the 64-byte header |
| `unknown format` | the header's magic bytes or version do not match, or a reserved header field is not zero |
| `sizes out of range` | the node count, text size, or decoded-string size the header describes does not fit `size`, or the `#!cpp '\0'` after the text or after the decoded strings is missing |
| `the check failed` | `check` is not `#!cpp image_check::none`, and the image fails it -- see [`image_check`](#image_check) |
!!! failure "Example messages"
```
[json.exception.parse_error.116] parse error: invalid json_document image: too short
```
```
[json.exception.parse_error.116] parse error: invalid json_document image: unknown format
```
```
[json.exception.parse_error.116] parse error: invalid json_document image: sizes out of range
```
```
[json.exception.parse_error.116] parse error: invalid json_document image: the check failed
```
## Complexity
Linear in the number of nodes, which are always copied into the document. With `#!cpp check == image_check::full`,
additionally linear in the combined length of the text and the decoded strings; `#!cpp image_check::bounds` and
`#!cpp image_check::none` do not read them.
## `image_check`
```cpp
using image_check = detail::view::image_check;
enum class image_check
{
full,
bounds,
none
};
```
How thoroughly `load()` validates `image` before trusting it.
| value | checks | guarantees |
|----------|--------------------------------------------------------------------------------------------------------------|------------|
| `full` | everything the parser itself guarantees: structure and bounds; that every string is valid UTF-8 (and, for a string still in the source text, that it contains no quote, backslash, or control character); and that every number token is well-formed and matches the value stored for it | reading and serializing a checked image is safe and always produces valid JSON, exactly as for a parsed document |
| `bounds` | structure and bounds only -- that every offset and count in the node index stays inside the image | reading and serializing stay memory-safe, but a crafted image can hold strings that are not valid UTF-8 or that serialize to invalid JSON ([`dump()`](../basic_json_view/dump.md) writes them unchanged or throws [`type_error.316`](../../home/exceptions.md#jsonexceptiontype_error316)), and numbers whose values differ from their text |
| `none` | nothing | images from a trusted source only -- reading a damaged image is undefined behavior |
`full` is the default and the right choice for an image from anything you do not fully control -- a file, a cache
shared with other processes, a peer on the network. `bounds` skips scanning the text and the decoded strings, so it
fits a cache your own process just wrote and reads straight back, where damage would mean a bug or a hardware fault
rather than adversarial input; it still cannot crash or read out of bounds. `none` skips validation entirely and
should only be used for an image you trust as much as your own memory.
## Notes
**Lifetime.** Overloads 1 and 2 borrow `image`: it must stay alive and byte-for-byte unchanged for as long as the
returned document, and any [view](../basic_json_view/index.md) taken from it, is used -- exactly like a document
[`parse()`](parse.md) borrowed its input for. Overload 3 avoids this by keeping the vector itself; see
[`owns_source`](owns_source.md).
!!! warning "Experimental"
The image format is versioned but not yet stable, and may change in an incompatible way before it is declared
stable; `load()` already rejects an image written by a different format version with `parse_error.116`
("unknown format"). Use images to cache a document within one build of the library, or to hand one to another
process running the *same* build on the *same* (little-endian) machine -- not as a long-term storage format.
**What `image_check::bounds` does not guarantee.** A bounds-checked image can never make `load()`,
[`root()`](root.md), element access, or [`materialize()`](../basic_json_view/materialize.md) read outside the image,
so those stay safe on a damaged one. It does *not* guarantee that the image describes valid JSON: a string
that a `full` check would have rejected can make [`dump()`](../basic_json_view/dump.md) write invalid UTF-8 or invalid
JSON, or throw `type_error.316`, and a number can read back with a value that does not match how it is spelled. Reserve `bounds` for images you already trust to be well-formed, and use it
only to skip the extra scan.
## Examples
??? example "Caching a document, ownership, and a rejected image"
The example below saves a parsed document as an image, checks that `load()` reproduces the original
[`dump()`](../basic_json_view/dump.md) without parsing, and shows the difference between
`load(std::move(image))` (owned) and `load(image)` (borrowed). It then damages one byte of the image and shows
`image_check::full` rejecting it with `parse_error.116`, while `image_check::bounds` -- meant for a cache the
process already trusts -- still reads it without going out of bounds.
```cpp
--8<-- "examples/basic_json_document__load.cpp"
```
Output:
```json
--8<-- "examples/basic_json_document__load.output"
```
## See also
- [save](save.md) - write the document as an image
- [owns_source](owns_source.md) - return whether the document holds its own copy of the text
- [parse](parse.md) - deserialize from JSON text instead of an image
- [Images](../../features/json_view.md#images) - why and when to use images
## Version history
- Added in version 3.13.0.
@@ -1,50 +0,0 @@
# <small>nlohmann::basic_json_document::</small>memory_usage
```cpp
std::size_t memory_usage() const noexcept;
```
Returns the number of bytes held by the document: the node index, the decoded-string buffer (for strings that
contain escapes), and, for an owned document, its copy of the source text.
## Return value
The number of bytes the document holds, `0` for a [discarded](is_discarded.md) document.
## Exception safety
No-throw guarantee: this function never throws exceptions.
## Complexity
Constant.
## Notes
The exact value depends on the platform, the allocator, and the library's own layout, and may change between
versions; do not rely on it being a specific number, and do not compare it across different builds or platforms.
Compare it for the same document over time, or between documents built with the same binary, instead -- for instance
to observe the effect of [`shrink_to_fit()`](shrink_to_fit.md).
## Examples
??? example
```cpp
--8<-- "examples/basic_json_document__memory_usage.cpp"
```
Output:
```json
--8<-- "examples/basic_json_document__memory_usage.output"
```
## See also
- [node_count](node_count.md) - the number of index entries
- [shrink_to_fit](shrink_to_fit.md) - release unused index capacity
## Version history
- Added in version 3.13.0.
@@ -1,49 +0,0 @@
# <small>nlohmann::basic_json_document::</small>node_count
```cpp
std::size_t node_count() const noexcept;
```
Returns the number of entries in the document's flat index.
## Return value
The number of index entries: one per value (of any type, at any nesting depth) plus one per object key. `0` for a
[discarded](is_discarded.md) document.
## Exception safety
No-throw guarantee: this function never throws exceptions.
## Complexity
Constant.
## Notes
Each index entry is [16 bytes](../../home/architecture.md#node-index-of-json-views), so `#!cpp node_count() * 16` is
the size of the index itself (part, but not all, of [`memory_usage()`](memory_usage.md), which also counts decoded
strings and, for an owned document, the text).
## Examples
??? example
```cpp
--8<-- "examples/basic_json_document__node_count.cpp"
```
Output:
```json
--8<-- "examples/basic_json_document__node_count.output"
```
## See also
- [memory_usage](memory_usage.md) - the number of bytes held by the document
- [shrink_to_fit](shrink_to_fit.md) - release unused index capacity
## Version history
- Added in version 3.13.0.
@@ -1,49 +0,0 @@
# <small>nlohmann::basic_json_document::</small>owns_source
```cpp
bool owns_source() const noexcept;
```
Returns whether the document holds its own copy of the parsed text, as opposed to borrowing the caller's buffer.
## Return value
`#!cpp true` if the document owns the text returned by [`source()`](source.md), `#!cpp false` if it borrows it (or if
the document is [discarded](is_discarded.md)).
## Exception safety
No-throw guarantee: this function never throws exceptions.
## Complexity
Constant.
## Notes
See the ownership table on [`parse`](parse.md#notes) for which inputs are borrowed and which are owned. A borrowed
document (`#!cpp owns_source() == false`) is only valid while the buffer it was parsed from is still alive.
## Examples
??? example
```cpp
--8<-- "examples/basic_json_document__owns_source.cpp"
```
Output:
```json
--8<-- "examples/basic_json_document__owns_source.output"
```
## See also
- [parse](parse.md) - deserialize from a compatible input
- [parse_copy](parse_copy.md) - deserialize a copy of a compatible input, always owned
- [source](source.md) - the parsed text
## Version history
- Added in version 3.13.0.
@@ -1,140 +0,0 @@
# <small>nlohmann::basic_json_document::</small>parse
```cpp
// (1)
template<typename InputType>
static basic_json_document parse(InputType&& input,
const bool allow_exceptions = true,
const bool ignore_comments = false,
const bool ignore_trailing_commas = false);
// (2)
template<typename IteratorType>
static basic_json_document parse(IteratorType first, IteratorType last,
const bool allow_exceptions = true,
const bool ignore_comments = false,
const bool ignore_trailing_commas = false);
```
1. Deserialize from a compatible input, borrowing or owning it depending on its value category and type (see Notes).
2. Deserialize from a pair of input iterators.
Both overloads accept exactly what [`BasicJsonType::parse()`](../basic_json/parse.md) accepts, with the same
`ignore_comments`/`ignore_trailing_commas` options, but build a [`basic_json_document`](index.md) (a flat index into
the input) instead of a tree of `BasicJsonType` values.
## Template parameters
`InputType`
: A compatible input, for instance:
- a `#!cpp std::string`, `#!cpp std::string_view`, or a C-style array of characters
- a pointer to a null-terminated string of single byte characters
- a container for which `#!cpp obj.data()` and `#!cpp obj.size()` give contiguous single-byte access, e.g.
`#!cpp std::vector<char>` or `#!cpp std::vector<std::uint8_t>`
- an `#!cpp std::istream` object, or anything else [`BasicJsonType::parse()`](../basic_json/parse.md) accepts
`IteratorType`
: a compatible iterator type, for instance a pair of pointers such as `ptr` and `ptr + len`, or a pair of
`#!cpp std::string::iterator`
## Parameters
`input` (in)
: Input to parse from.
`allow_exceptions` (in)
: whether to throw exceptions in case of a parse error (optional, `#!cpp true` by default)
`ignore_comments` (in)
: whether comments should be ignored and treated like whitespace (`#!cpp true`) or yield a parse error
(`#!cpp false`); (optional, `#!cpp false` by default)
`ignore_trailing_commas` (in)
: whether trailing commas in arrays or objects should be ignored and treated like whitespace (`#!cpp true`) or
yield a parse error (`#!cpp false`); (optional, `#!cpp false` by default)
`first` (in)
: iterator to the start of a character range
`last` (in)
: iterator to the end of a character range
## Return value
The parsed document. If `allow_exceptions` is `#!cpp false` and the input is not valid JSON, the returned document is
discarded; see [`is_discarded`](is_discarded.md).
## Exceptions
Throws the same exception [`BasicJsonType::parse()`](../basic_json/parse.md) throws for the same input and options --
the same exception id, message, and position -- because on a failing input the library's own parser is run on the
same bytes to produce the diagnostic. Additionally throws
[`out_of_range.416`](../../home/exceptions.md#jsonexceptionout_of_range416) if the input is 4 GiB or larger, a size
[`BasicJsonType::parse()`](../basic_json/parse.md) does not reject.
## Complexity
Linear in the length of the input.
## Notes
**Ownership.** Whether the document borrows `input` or owns a copy of it depends on its value category and type:
| `input` | ownership |
|--------------------------------------------------------------------------------------|--------------------------------------------------------------|
| lvalue byte container (`std::string`, `std::vector<char>`, ...), `std::string_view`, C string, character array | **borrowed** -- `input` must outlive the document |
| rvalue `#!cpp std::string` | **owned**, moved in without a copy |
| rvalue byte container other than `#!cpp std::string` | **owned**, copied |
| stream, wide string, or anything else read through the general input adapter | **owned**, read into a buffer (a stream is read to its end) |
For overload (2), a pair of pointers to single-byte integers (e.g. `#!cpp const char*`, `#!cpp std::uint8_t*`) is
borrowed. From C++20 on, so is any other contiguous iterator over single bytes, such as
`#!cpp std::vector<char>::iterator` or `#!cpp std::string::const_iterator`. Before C++20 these iterators cannot be
told apart from other class-type iterators, so their range is read into an owned buffer, as is any non-contiguous
range (e.g. of a `#!cpp std::list<char>`).
See [`owns_source`](owns_source.md) to check which happened after a call, and the
[feature page](../../features/json_view.md) for the reasoning.
**Numbers.** As for [`BasicJsonType::parse()`](../basic_json/parse.md), an integer literal too large for the 64-bit
integer type becomes a floating-point value.
## Examples
??? example "Example: (1) borrowed vs. owned input, and errors identical to `BasicJsonType::parse()`"
```cpp
--8<-- "examples/basic_json_document__parse.cpp"
```
Output:
```json
--8<-- "examples/basic_json_document__parse.output"
```
??? example "Example: (2) parse an iterator range (no NUL terminator required)"
```cpp
--8<-- "examples/basic_json_document__parse_iterator_pair.cpp"
```
Output:
```json
--8<-- "examples/basic_json_document__parse_iterator_pair.output"
```
## See also
- [parse_copy](parse_copy.md) - deserialize a copy of a compatible input
- [accept](accept.md) - check whether the input is valid JSON
- [read](read.md) - (re-)parse into this document, reusing its memory
- [owns_source](owns_source.md) - return whether the document holds its own copy of the text
- [load](load.md) - read a document from an image instead of parsing JSON text
- [`BasicJsonType::parse`](../basic_json/parse.md) - the corresponding function of `basic_json`
## Version history
- Added in version 3.13.0.
@@ -1,77 +0,0 @@
# <small>nlohmann::basic_json_document::</small>parse_copy
```cpp
template<typename InputType>
static basic_json_document parse_copy(InputType&& input,
const bool allow_exceptions = true,
const bool ignore_comments = false,
const bool ignore_trailing_commas = false);
```
Deserialize from a compatible input, always taking the document's own copy of it, regardless of the value category or
type of `input`. Unlike [`parse()`](parse.md), the returned document never depends on `input` staying alive.
## Template parameters
`InputType`
: A compatible input; see [`parse`](parse.md#template-parameters).
## Parameters
`input` (in)
: Input to parse from.
`allow_exceptions` (in)
: whether to throw exceptions in case of a parse error (optional, `#!cpp true` by default)
`ignore_comments` (in)
: whether comments should be ignored and treated like whitespace (`#!cpp true`) or yield a parse error
(`#!cpp false`); (optional, `#!cpp false` by default)
`ignore_trailing_commas` (in)
: whether trailing commas in arrays or objects should be ignored and treated like whitespace (`#!cpp true`) or
yield a parse error (`#!cpp false`); (optional, `#!cpp false` by default)
## Return value
The parsed document, with [`owns_source()`](owns_source.md) `#!cpp true`. If `allow_exceptions` is `#!cpp false` and
the input is not valid JSON, the returned document is discarded; see [`is_discarded`](is_discarded.md).
## Exceptions
Same as [`parse`](parse.md#exceptions).
## Complexity
Linear in the length of the input.
## Notes
`parse_copy()` accepts and rejects exactly what [`parse()`](parse.md) does, and classifies numbers the same way; it
only differs in that the input is always copied rather than sometimes borrowed. Prefer [`parse()`](parse.md) when the
input's lifetime already covers the document's, since it avoids the copy for borrowed inputs.
## Examples
??? example
The example below returns a document from a function whose local buffer would otherwise not outlive it.
```cpp
--8<-- "examples/basic_json_document__parse_copy.cpp"
```
Output:
```json
--8<-- "examples/basic_json_document__parse_copy.output"
```
## See also
- [parse](parse.md) - deserialize from a compatible input, borrowing it where possible
- [owns_source](owns_source.md) - return whether the document holds its own copy of the text
## Version history
- Added in version 3.13.0.
@@ -1,102 +0,0 @@
# <small>nlohmann::basic_json_document::</small>push_back
```cpp
template<typename V>
view_type push_back(view_type array, V&& value);
```
Appends `value` as a new last element of `array`. A [null](../basic_json_view/is_null.md) `array` first becomes an
empty array, the same way [`set`](set.md) turns a null `object` into an empty object.
`value` is accepted three ways: a [`basic_json_view`](../basic_json_view/index.md) of *any* document -- read-only or
editable, and it does not have to be `array`'s own document -- which is copied so that nothing is shared with the
source document afterward; a `BasicJsonType` value; or anything `BasicJsonType` can be constructed from (numbers,
strings, `#!cpp bool`, `#!cpp nullptr`, containers, ...).
Only an **editable** document (`#!cpp Editable == true`, e.g. [`json_editable_document`](../json_editable_document.md))
has `push_back`; calling it on a read-only `basic_json_document` fails to compile (`#!cpp static_assert`).
## Template parameters
`V`
: the type of `value`, deduced; see above for what is accepted.
## Parameters
`array` (in)
: the array (or null value) to append to
`value` (in)
: the value to append
## Return value
a view of the new last element of `array`, now holding `value`
## Exception safety
Basic exception safety: `value` is fully encoded -- including the checks below -- into storage owned by the document
before anything already reachable from [`root()`](root.md) is touched, so a failure while encoding `value` (an
invalid argument, or `#!cpp std::bad_alloc`) leaves the document completely unchanged, other than memory allocated
for the encoding that is not reclaimed. A failure of a later allocation -- while `array` switches from its parsed
layout to a growable block, or while that block grows, see [Notes](#notes) -- can still leave a partial effect, such
as a null `array` argument already turned into an empty array even though `value` itself was not appended.
## Exceptions
Throws [`type_error.308`](../../home/exceptions.md#jsonexceptiontype_error308) if `array` is neither an array nor
null -- the same message [`BasicJsonType::push_back`](../basic_json/push_back.md) throws for the same type. Throws
[`invalid_iterator.202`](../../home/exceptions.md#jsonexceptioninvalid_iterator202) ("view does not belong to this
document") if `array` is a [discarded](../basic_json_view/is_discarded.md) view or a view of a *different* document.
Throws [`type_error.302`](../../home/exceptions.md#jsonexceptiontype_error302) if `value` is a
[discarded](../basic_json_view/is_discarded.md) view or a [discarded](../basic_json/is_discarded.md) `BasicJsonType`
value, and [`type_error.319`](../../home/exceptions.md#jsonexceptiontype_error319) if `value` is (or contains) a
binary value -- `BasicJsonType` can hold one, but a `json_document` cannot. Throws
[`type_error.316`](../../home/exceptions.md#jsonexceptiontype_error316) if `value` is (or contains) a string that is
not valid UTF-8, with the same message [`BasicJsonType::dump()`](../basic_json/dump.md) gives for that string.
## Complexity
Amortized constant, plus time linear in the size of `value` to encode it into the document's storage (constant for
a scalar, linear in the number of nested values for an array or object): the elements of `array` move to a growable
block of links the first time it is appended to (or [`set`](set.md) on), and that block itself grows -- doubling its
capacity, so the cost of growing it amortizes to constant per element -- only once it runs out of room. See
[Notes](#notes).
## Notes
Like [`set`](set.md) on a member or an element, `push_back` never moves an existing element itself -- only where
`array`'s *links* to its elements live -- so a view of an existing element of `array` stays valid across a
`push_back`, but any iterator already taken over `array` is invalidated, since it was walking the old layout. See
[Edits](index.md#edits) for what stays valid across an edit in general.
## Examples
??? example
The example below appends records to an array one at a time, as they might arrive from a stream of events,
without ever building a `BasicJsonType` value for the array or for the records already in it, and shows that a
view taken from an earlier `push_back` still refers to the same element once later ones have run.
```cpp
--8<-- "examples/basic_json_document__push_back.cpp"
```
Output:
```json
--8<-- "examples/basic_json_document__push_back.output"
```
## See also
- [set](set.md) - replace a value, or set an object member, an array element, or the value a JSON pointer refers to
- [insert](insert.md) - insert an element into an array before a given position
- [erase](erase.md) - remove an object member, an array element, or the value a JSON pointer refers to
- [root](root.md) - the view of the root value
- [`BasicJsonType::push_back`](../basic_json/push_back.md) - the corresponding function of `basic_json`
- [Edits](index.md#edits) - what an edit guarantees, for every overload
## Version history
- Added in version 3.13.0.
@@ -1,77 +0,0 @@
# <small>nlohmann::basic_json_document::</small>read
```cpp
template<typename InputType>
void read(InputType&& input,
const bool allow_exceptions = true,
const bool ignore_comments = false,
const bool ignore_trailing_commas = false);
```
(Re-)parses `input` into `#!cpp *this`, discarding the document's previous value and reusing its memory (the node
index, the decoded-string buffer, and, if applicable, the owned copy of the text) rather than allocating a fresh
document. [`parse()`](parse.md) is implemented in terms of this function, applied to a default-constructed document.
## Template parameters
`InputType`
: A compatible input; see [`parse`](parse.md#template-parameters).
## Parameters
`input` (in)
: Input to parse from.
`allow_exceptions` (in)
: whether to throw exceptions in case of a parse error (optional, `#!cpp true` by default)
`ignore_comments` (in)
: whether comments should be ignored and treated like whitespace (`#!cpp true`) or yield a parse error
(`#!cpp false`); (optional, `#!cpp false` by default)
`ignore_trailing_commas` (in)
: whether trailing commas in arrays or objects should be ignored and treated like whitespace (`#!cpp true`) or
yield a parse error (`#!cpp false`); (optional, `#!cpp false` by default)
## Exceptions
Same as [`parse`](parse.md#exceptions).
## Complexity
Linear in the length of the input.
## Notes
Every view taken from `#!cpp *this` before the call -- including the previous [`root()`](root.md) -- is invalidated,
whether or not the new parse succeeds; take fresh views from [`root()`](root.md) afterward.
`input` is borrowed or owned by the same rules as [`parse()`](parse.md#notes); a document can borrow on one call and
own on the next, since ownership is decided freshly each time.
## Examples
??? example
The example below parses a sequence of messages into the same document, reusing its memory instead of allocating
a new document for each one.
```cpp
--8<-- "examples/basic_json_document__read.cpp"
```
Output:
```json
--8<-- "examples/basic_json_document__read.output"
```
## See also
- [parse](parse.md) - deserialize from a compatible input
- [root](root.md) - the view of the root value
- [load](load.md) - read a document from an image instead of parsing JSON text
## Version history
- Added in version 3.13.0.
@@ -1,50 +0,0 @@
# <small>nlohmann::basic_json_document::</small>root
```cpp
view_type root() const noexcept;
```
Returns a view of the root value of the document.
## Return value
A [`view_type`](index.md#member-types) (i.e. `#!cpp basic_json_view<BasicJsonType>`) for the root value, or a
discarded view if the document is [discarded](is_discarded.md).
## Exception safety
No-throw guarantee: this function never throws exceptions.
## Complexity
Constant.
## Notes
`root()` is a cheap handle into the document's index, not a copy of anything; call it as often as needed. The
returned view is valid under the same conditions as any other view of the document -- see
[Object inspection](../basic_json_view/index.md) -- in particular, it is invalidated by the next
[`read()`](read.md) or [`shrink_to_fit()`](shrink_to_fit.md) on this document.
## Examples
??? example
```cpp
--8<-- "examples/basic_json_document__root.cpp"
```
Output:
```json
--8<-- "examples/basic_json_document__root.output"
```
## See also
- [is_discarded](is_discarded.md) - return whether the last parse failed
- [materialize](../basic_json_view/materialize.md) - build the `BasicJsonType` value of a subtree
## Version history
- Added in version 3.13.0.
@@ -1,104 +0,0 @@
# <small>nlohmann::basic_json_document::</small>save
```cpp
std::vector<std::uint8_t> save() const;
```
Writes the document as an *image*: a byte buffer that [`load`](load.md) reads back without parsing. The image holds
the node index, the source text (plus, for an edited document, the number tokens edits wrote), and the decoded
strings (plus the strings edits wrote) -- everything [`root()`](root.md) needs, with nothing left to parse.
An edited document is written in its *current* state, with its values in document order, the way the library's own
parser would have produced them for that JSON text: a member [`set`](set.md) added goes at the end, an
[`erase`](erase.md)d member leaves no trace, and a float that is not finite (NaN or positive/negative infinity)
becomes null, the same substitution [`dump()`](../basic_json_view/dump.md) makes. The same document always saves to
the same bytes -- also across `BasicJsonType` and `#!cpp Editable`, since the image reflects document order and
values only, not which specialization produced them.
## Return value
The image, as a `#!cpp std::vector<std::uint8_t>`. Pass it, or a pointer to its data together with its size, to
[`load`](load.md) to read the document back.
## Exception safety
Strong guarantee: `save()` does not modify `#!cpp *this` (it is `#!cpp const`), so if it throws, the document is left
exactly as it was, and the partially built image is discarded with the exception.
## Exceptions
Throws [`type_error.320`](../../home/exceptions.md#jsonexceptiontype_error320) if the document is
[discarded](is_discarded.md) -- a default-constructed document, or one a failed [`parse()`](parse.md)/
[`read()`](read.md) with `allow_exceptions == false` left discarded.
On a big-endian target, throws `type_error.320` with a different message instead: the image format is little-endian
only (see [Notes](#notes)).
Throws [`out_of_range.416`](../../home/exceptions.md#jsonexceptionout_of_range416) if the node count, the text, or
the decoded strings of the image would individually reach 4 GiB -- the same 32-bit offsets
[`parse()`](parse.md#exceptions) and, for edits, [`set`](set.md)/[`push_back`](push_back.md) are already limited to.
!!! failure "Example messages"
```
[json.exception.type_error.320] cannot save a discarded json_document
```
```
[json.exception.type_error.320] json_document images need a little-endian target
```
```
[json.exception.out_of_range.416] images of 4 GiB or more are not supported by json_document
```
## Complexity
Linear in the size of the document: the number of nodes, plus the length of the text and the decoded strings that end
up in the image.
## Notes
**Format.** The image begins with a 64-byte header (the magic bytes `#!cpp "NJVI"`, a version number, the node count,
and the sizes of the text and the decoded strings, all little-endian), followed by the nodes
([16 bytes each](../../home/architecture.md#node-index-of-json-views)), the text and a `#!cpp '\0'`, and the decoded
strings and a `#!cpp '\0'`. [`load`](load.md) checks the header, and the sizes it describes, before reading anything
else -- see [`load`'s Exceptions](load.md#exceptions).
!!! warning "Experimental"
The image format is versioned but not yet stable: it may change in an incompatible way before it is declared
stable. Use images to cache a document within one build of the library, or to hand one to another process running
the *same* build on the *same* (little-endian) machine -- not as a long-term storage format. Keep the original
JSON text if you need to read a saved document back with a future library version.
**Little-endian only.** The image is written as raw little-endian bytes, with no byte-swapping. `save()` (and
[`load`](load.md)) throw `type_error.320` on a big-endian target rather than silently produce bytes a big-endian
reader could not interpret correctly.
## Examples
??? example "Caching a parsed document as an image"
The example below saves a parsed configuration as an image -- the way a service might cache one to answer later
requests without parsing the text again -- and confirms that loading it back gives exactly the same result as
parsing did, and that saving is deterministic.
```cpp
--8<-- "examples/basic_json_document__save.cpp"
```
Output:
```json
--8<-- "examples/basic_json_document__save.output"
```
## See also
- [load](load.md) - read an image written by `save()`
- [owns_source](owns_source.md) - return whether the document holds its own copy of the text
- [`basic_json_view::dump`](../basic_json_view/dump.md) - serialize the document to JSON text instead of an image
- [Images](../../features/json_view.md#images) - why and when to use images
## Version history
- Added in version 3.13.0.
@@ -1,194 +0,0 @@
# <small>nlohmann::basic_json_document::</small>set
```cpp
// (1)
template<typename V>
view_type set(view_type target, V&& value);
// (2)
template<typename V>
view_type set(view_type object, string_view_t key, V&& value);
// (3)
template<typename I, typename V>
view_type set(view_type array, I idx, V&& value);
// (4)
template<typename V>
view_type set(const json_pointer& ptr, V&& value);
```
Only an **editable** document (`#!cpp Editable == true`, e.g. [`json_editable_document`](../json_editable_document.md))
has `set`; calling it on a read-only `basic_json_document` fails to compile (`#!cpp static_assert`).
1. Replaces the value `target` refers to with `value`.
2. Sets the member `key` of the object `object` to `value`: assigns it if `object` already has a member with this
key -- the first one, should the key occur more than once, and the later duplicates are then dropped (see the
[Notes](#notes) below) -- or appends a new member at the end otherwise. A [null](../basic_json_view/is_null.md)
`object` first becomes an empty object.
3. Assigns `value` to the element at index `idx` of the array `array`, which must already exist (`#!cpp idx <
array.size()`).
4. Sets the value the JSON pointer `ptr` refers to, relative to [`root()`](root.md), to `value`. The *parent* of the
target must already exist: an object member is set as in 2. (added if it does not exist yet), an array element is
assigned as in 3., and a last reference token of `#!cpp "-"`, or equal to the size of the array, appends `value`
instead, exactly as [`push_back`](push_back.md) would. An empty `ptr` sets [`root()`](root.md) itself, as in 1.
In every overload, `value` is accepted three ways: a [`basic_json_view`](../basic_json_view/index.md) of *any*
document -- read-only or editable, and it does not have to be `target`'s/`object`'s/`array`'s own document -- which
is copied so that nothing is shared with the source document afterward; a `BasicJsonType` value; or anything
`BasicJsonType` can be constructed from (numbers, strings, `#!cpp bool`, `#!cpp nullptr`, containers, ...).
## Template parameters
`V`
: the type of `value`, deduced; see above for what is accepted.
`I`
: an integral type other than `#!cpp bool`, deduced (overloads taking a `#!cpp bool` or a non-integral type for
`idx` do not participate in overload resolution).
## Parameters
`target` (in)
: the value to replace
`object` (in)
: the object (or null value) whose member to set
`array` (in)
: the array whose element to assign
`key` (in)
: the key of the member to set
`idx` (in)
: the index of the element to assign; a negative value throws (see [Exceptions](#exceptions))
`ptr` (in)
: a JSON pointer to the value to set, relative to `root()`
`value` (in)
: the new value
## Return value
1. a view of `target`, now holding `value`
2. a view of the member `key` of `object`, now holding `value`
3. a view of the element `idx` of `array`, now holding `value`
4. a view of the value `ptr` refers to, now holding `value`
## Exception safety
Basic exception safety: `value` is fully encoded -- including the checks below -- into storage owned by the document
before anything already reachable from [`root()`](root.md) is touched, so a failure while encoding `value` (an
invalid argument, or `#!cpp std::bad_alloc`) leaves the document completely unchanged, other than memory allocated
for the encoding that is not reclaimed. A failure of a later allocation -- while an edited array or object switches
from its parsed layout to a growable block, see [Notes](#notes) -- can still leave a partial effect, such as a
[null](../basic_json_view/is_null.md) `object`/`array` argument already turned into an empty object/array even
though `value` itself was not linked in.
## Exceptions
1. Throws [`type_error.302`](../../home/exceptions.md#jsonexceptiontype_error302) if `value` is a
[discarded](../basic_json_view/is_discarded.md) view, or a [discarded](../basic_json/is_discarded.md)
`BasicJsonType` value (e.g. `#!cpp BasicJsonType(value_t::discarded)`) -- an object or array `value`, of either
kind, is fine and is encoded as a whole subtree.
2. Throws [`type_error.305`](../../home/exceptions.md#jsonexceptiontype_error305) if `object` is neither an object
nor null -- the same message [`operator[]`](../basic_json_view/operator%5B%5D.md) throws for a string argument on
such a value. Throws [`type_error.316`](../../home/exceptions.md#jsonexceptiontype_error316) if `key` is not
valid UTF-8, with the same message [`BasicJsonType::dump()`](../basic_json/dump.md) gives for that string.
Also throws what 1. throws for `value`.
3. Throws `type_error.305` if `array` is not an array -- the same message `operator[]` throws for a numeric argument
on such a value. Throws [`out_of_range.401`](../../home/exceptions.md#jsonexceptionout_of_range401) if `idx` is
negative, or if `#!cpp idx >= array.size()`. Also throws what 1. throws for `value`.
4. Throws what [`at`](../basic_json_view/at.md) throws (overload 3) for resolving `ptr`'s parent, except that a
missing object member or an array index equal to the array's size at the very last reference token is not an
error there (it becomes a new member or an appended element) instead of
[`out_of_range.403`](../../home/exceptions.md#jsonexceptionout_of_range403)/[`out_of_range.402`](../../home/exceptions.md#jsonexceptionout_of_range402).
For the last reference token itself: if the parent is an object (or a primitive value, where it throws
`type_error.305`), throws what 2. throws; if the parent is an array, throws what 3. throws for an index that is
out of range, or, for a token that is not a valid array index,
[`parse_error.106`](../../home/exceptions.md#jsonexceptionparse_error106) (a leading `#!cpp '0'`),
[`parse_error.109`](../../home/exceptions.md#jsonexceptionparse_error109) (not a number),
[`out_of_range.410`](../../home/exceptions.md#jsonexceptionout_of_range410) (too large for `size_type`), or
[`out_of_range.404`](../../home/exceptions.md#jsonexceptionout_of_range404) (an empty token). Also throws what 1.
throws for `value`.
Every overload also throws [`type_error.319`](../../home/exceptions.md#jsonexceptiontype_error319) if `value` is (or
contains) a binary value -- `BasicJsonType` can hold one, but a `json_document` cannot -- and
[`invalid_iterator.202`](../../home/exceptions.md#jsonexceptioninvalid_iterator202) ("view does not belong to this
document") if `target`/`object`/`array` is a [discarded](../basic_json_view/is_discarded.md) view or a view of a
*different* document (overloads 1-3 only; overload 4 always starts from this document's own [`root()`](root.md)).
## Complexity
1. Linear in the size of `value` (encoding it into the document's storage): constant for a scalar, linear in the
number of nested values for an array or object. If `target` is itself an array or object that spans more than one
node in its parent's original, unedited layout, and `value` is a scalar, replacing it additionally costs time
linear in the number of elements of that parent, the *first* time -- see [Notes](#notes).
2. Linear in the number of members of `object`, to find an existing member with `key`, plus the complexity of 1. for
`value`.
3. Constant, plus the complexity of 1. for `value`.
4. Linear in the number of reference tokens of `ptr` and, for each token, in the number of members of the object at
that level or the index into the array (as [`at`](../basic_json_view/at.md)), plus the complexity of 2. or 3. for
the last token.
## Notes
!!! info "Duplicate keys"
If `object` already has more than one member with `key` (2.), the *first* one is assigned `value` and every
later member with the same key is removed -- so that a lookup, an iteration, and
[`materialize()`](../basic_json_view/materialize.md) of `object` afterward all agree on a single value for
`key`, the same way [`operator[]`](../basic_json_view/operator%5B%5D.md) already picks the first occurrence of a
duplicate key for reading. See the [Notes on duplicate keys](../basic_json_view/operator%5B%5D.md#notes) of
`operator[]`.
Setting a member (2.) or an element (3., through 4.) of an array or object whose elements have not been edited
before switches it from its parsed layout to a growable block holding links to its elements; a later
[`push_back`](push_back.md) or `set` on the same container reuses that block, growing it (amortized constant time)
only once it runs out of room. This never moves an element itself -- only where the container's *links* to its
elements live -- so a view of an element stays valid, but any iterator already taken over the container is
invalidated, since it was walking the old layout. See [Edits](index.md#edits) for what stays valid across an edit in
general.
The same switch happens, for the same reason, when overload 1. replaces a multi-node array/object value with a
scalar: the *parent's* element sequence is what has to switch to links, not `target` itself, because the parent
originally stepped over `target`'s whole subtree by its node count, which no longer applies once `target` is a
one-node scalar.
## Examples
??? example "Example: (1)/(2)/(3)/(4) replace a value, set a member, assign an element, set via a JSON pointer"
The example below edits a small configuration document -- replacing a value, adding an object member, assigning
an array element, and reaching a field through a JSON pointer -- and shows what
[`dump()`](../basic_json_view/dump.md) preserves that is lost once the same edits are made on a `BasicJsonType`
value instead: the order object members were written in, and the exact spelling of a number that was never
touched.
```cpp
--8<-- "examples/basic_json_document__set.cpp"
```
Output:
```json
--8<-- "examples/basic_json_document__set.output"
```
## See also
- [push_back](push_back.md) - append to an array
- [insert](insert.md) - insert an element into an array
- [erase](erase.md) - remove an object member, an array element, or the value a JSON pointer refers to
- [root](root.md) - the view of the root value, the starting point of overload 4
- [`basic_json_view::dump`](../basic_json_view/dump.md) - serialize the document, keeping an untouched number's
spelling with `#!cpp number_format::source`
- [Edits](index.md#edits) - what an edit guarantees, for every overload
- [Editing a document](../../features/json_view.md#editing-a-document) - why editable documents keep the source
text's order and number spelling
## Version history
- Added in version 3.13.0.
@@ -1,58 +0,0 @@
# <small>nlohmann::basic_json_document::</small>shrink_to_fit
```cpp
void shrink_to_fit();
```
Releases capacity that is no longer needed, both of the node index and of the buffer for decoded strings (strings that
contained escape sequences), e.g. after [`read()`](read.md) replaced a large document with a much smaller one. Like
`#!cpp std::vector::shrink_to_fit()`, this is a non-binding request: the library may keep more capacity than strictly
necessary.
## Exception safety
Strong guarantee: if an exception is thrown, there are no changes to the document.
## Exceptions
May throw `#!cpp std::bad_alloc` if the reallocation fails; on exception, the document is unchanged.
## Complexity
Linear in [`node_count()`](node_count.md) plus the length of the decoded strings.
## Notes
!!! warning "Invalidates views"
Unlike moving the document, `shrink_to_fit()` **invalidates every view taken from this document before the
call**, including a previously obtained [`root()`](root.md): the node index is moved into a new, smaller
allocation, and the old one is freed. Take a fresh view from [`root()`](root.md) after calling this function.
This is unlike `#!cpp std::vector::shrink_to_fit()`, which promises nothing about validity but in practice often
leaves iterators alone when it did not need to reallocate; here, an implementation that avoids a reallocation when
possible would be an internal optimization only, not a guarantee to rely on.
## Examples
??? example
```cpp
--8<-- "examples/basic_json_document__shrink_to_fit.cpp"
```
Output:
```json
--8<-- "examples/basic_json_document__shrink_to_fit.output"
```
## See also
- [node_count](node_count.md) - the number of index entries
- [memory_usage](memory_usage.md) - the number of bytes held by the document
- [root](root.md) - the view of the root value
## Version history
- Added in version 3.13.0.
@@ -1,48 +0,0 @@
# <small>nlohmann::basic_json_document::</small>source
```cpp
view_type::string_view_t source() const noexcept;
```
Returns the parsed text, whether it is borrowed from the caller or owned by the document.
## Return value
A `#!cpp string_view_t` (`#!cpp std::string_view` on C++17 and newer) over the parsed text, or an empty one if the
document is [discarded](is_discarded.md).
## Exception safety
No-throw guarantee: this function never throws exceptions.
## Complexity
Constant.
## Notes
For a borrowed document, `source()` points directly into the caller's buffer, so it is only valid while that buffer
is; see [`owns_source`](owns_source.md).
## Examples
??? example
```cpp
--8<-- "examples/basic_json_document__source.cpp"
```
Output:
```json
--8<-- "examples/basic_json_document__source.output"
```
## See also
- [owns_source](owns_source.md) - return whether the document holds its own copy of the text
- [source_offset](../basic_json_view/source_offset.md) - byte offset of a value in the source text
## Version history
- Added in version 3.13.0.
-134
View File
@@ -1,134 +0,0 @@
# <small>nlohmann::basic_json_view::</small>at
```cpp
// (1)
basic_json_view at(string_view_t key) const;
basic_json_view at(const char* key) const;
basic_json_view at(const string_t& key) const;
// (2)
basic_json_view at(size_type idx) const;
basic_json_view at(int idx) const;
// (3)
basic_json_view at(const json_pointer& ptr) const;
```
1. Returns the value of the object member with key `key` -- the first one, should the key occur more than once (see
[Notes on duplicate keys](operator[].md#notes)).
2. Returns the array element at index `idx`.
3. Returns the value a JSON pointer `ptr` refers to, starting at this value.
## Parameters
`key` (in)
: object key of the element to access
`idx` (in)
: index of the element to access
`ptr` (in)
: JSON pointer to the element to access
## Return value
1. the value of the first member with key `key`
2. the element at index `idx`
3. the value `ptr` resolves to, starting at this value
## Exception safety
Strong exception safety: if an exception is thrown, there are no changes to the view or the document it refers to.
## Exceptions
1. The function can throw the following exceptions, both with the same message as the corresponding call to
[`BasicJsonType::at`](../basic_json/at.md):
- Throws [`type_error.304`](../../home/exceptions.md#jsonexceptiontype_error304) if the value is not an object.
- Throws [`out_of_range.403`](../../home/exceptions.md#jsonexceptionout_of_range403) if no member has key `key`.
2. The function can throw the following exceptions, both with the same message as the corresponding call to
[`BasicJsonType::at`](../basic_json/at.md):
- Throws [`type_error.304`](../../home/exceptions.md#jsonexceptiontype_error304) if the value is not an array.
- Throws [`out_of_range.401`](../../home/exceptions.md#jsonexceptionout_of_range401) if `#!cpp idx >= size()`.
3. The function can throw the following exceptions, all with the same message as the corresponding call to
[`BasicJsonType::at`](../basic_json/at.md):
- Throws [`parse_error.106`](../../home/exceptions.md#jsonexceptionparse_error106) if an array index in `ptr`
begins with `#!cpp '0'`.
- Throws [`parse_error.109`](../../home/exceptions.md#jsonexceptionparse_error109) if an array index in `ptr` is
not a number.
- Throws [`out_of_range.401`](../../home/exceptions.md#jsonexceptionout_of_range401) if an array index in `ptr`
is out of range.
- Throws [`out_of_range.402`](../../home/exceptions.md#jsonexceptionout_of_range402) if a reference token is
`#!cpp "-"` at an array -- `at` never inserts an element, so `#!cpp "-"` is always invalid.
- Throws [`out_of_range.403`](../../home/exceptions.md#jsonexceptionout_of_range403) if a reference token names
an object member that does not exist.
- Throws [`out_of_range.404`](../../home/exceptions.md#jsonexceptionout_of_range404) if `ptr` cannot be resolved
because a reference token is used on a primitive value.
None of these exceptions carry a [`JSON_DIAGNOSTICS`](../macros/json_diagnostics.md) path: the view has no
`BasicJsonType` value to point at, so the exception is created without one, even if `BasicJsonType` was built with
`JSON_DIAGNOSTICS` enabled.
## Complexity
1. Linear in the number of members: as for [`ordered_json`](../ordered_json.md), members are compared one after
another, in document order, stopping at the first match. Each comparison first checks the key's length --
already known from the index, without reading the key bytes -- before comparing its content.
Objects with 128 or more members get a hash index while parsing, so that a lookup in them takes constant time
on average.
2. Linear in `idx`: elements are skipped one at a time from the first one, since they are not a fixed size in the
index (unlike `BasicJsonType`'s array, which is random-access).
3. Linear in the number of reference tokens of `ptr` and, for each token, in the number of members of the object at
that level (as 1.) or the index into the array (as 2.).
## Notes
Unlike [`operator[]`](operator[].md), which returns a [discarded](is_discarded.md) view for a missing key or an
out-of-range index, `at` always throws -- exactly as `BasicJsonType::at` does, and with the same messages, so
existing error handling written against `BasicJsonType::at` keeps working unchanged when switched to a view. This
also holds for overload 3: unlike [`operator[]`](operator[].md) with a JSON pointer, which returns a discarded view
for a missing key or an out-of-range index, `at` throws for those too (`out_of_range.403`/`out_of_range.401`).
## Examples
??? example "Example: (1)/(2) access specified element with bounds checking"
The example below reads required fields out of a service configuration with `at`, and shows that the exceptions
it throws -- for a wrong type and for a missing key -- carry the same messages
[`BasicJsonType::at`](../basic_json/at.md) would produce for the same JSON text.
```cpp
--8<-- "examples/basic_json_view__at.cpp"
```
Output:
```json
--8<-- "examples/basic_json_view__at.output"
```
??? example "Example: (3) access specified element via JSON pointer with bounds checking"
The example below shows that `at` with a JSON pointer throws exactly the exceptions, with exactly the messages,
that [`BasicJsonType::at`](../basic_json/at.md) throws for the same pointer and the same document.
```cpp
--8<-- "examples/basic_json_view__at_json_pointer.cpp"
```
Output:
```json
--8<-- "examples/basic_json_view__at_json_pointer.output"
```
## See also
- [operator[]](operator[].md) - access specified element (returns a discarded view instead of throwing)
- [front](front.md), [back](back.md) - access the first or last element
- [`BasicJsonType::at`](../basic_json/at.md) - the corresponding function of `basic_json`
- [`json_pointer`](../json_pointer/index.md) - JSON pointer type used by overload 3
## Version history
- Added in version 3.13.0.
@@ -1,64 +0,0 @@
# <small>nlohmann::basic_json_view::</small>back
```cpp
basic_json_view back() const;
```
Returns the last element of an array, the last member value of an object, or the value itself if it is primitive
(as for [`BasicJsonType::back()`](../basic_json/back.md), a primitive value is a range of one element).
## Return value
The last element or member value. For a primitive value (number, string, boolean), the value itself.
## Exception safety
Strong exception safety: if an exception is thrown, there are no changes to the view or the document it refers to.
## Exceptions
Throws [`invalid_iterator.214`](../../home/exceptions.md#jsonexceptioninvalid_iterator214) if the view is
[null](is_null.md) or [discarded](is_discarded.md), or if it is an empty array or object.
This exception does not carry a [`JSON_DIAGNOSTICS`](../macros/json_diagnostics.md) path: the view has no
`BasicJsonType` value to point at, so the exception is created without one, even if `BasicJsonType` was built with
`JSON_DIAGNOSTICS` enabled.
## Complexity
Linear in the size of the array or object: unlike [`front()`](front.md), which only ever looks at the first
element, `back()` has to walk every element to find where they end, since elements are not a fixed size in the
index.
## Notes
Unlike [`BasicJsonType::back()`](../basic_json/back.md), which has undefined behavior for an empty array or object,
`back()` throws `invalid_iterator.214` in that case -- the same way it already does for `#!json null` and for a
discarded view, where `BasicJsonType::back()` also throws.
## Examples
??? example
The example below reads only the final status of a build log with `back()`. Even though `back()` is linear in
the number of events (unlike [`front()`](front.md), which is constant), it still avoids building a
`BasicJsonType` value for the events that are not needed.
```cpp
--8<-- "examples/basic_json_view__back.cpp"
```
Output:
```json
--8<-- "examples/basic_json_view__back.output"
```
## See also
- [front](front.md) - access the first element
- [`BasicJsonType::back`](../basic_json/back.md) - the corresponding function of `basic_json`
## Version history
- Added in version 3.13.0.
@@ -1,52 +0,0 @@
# <small>nlohmann::basic_json_view::</small>basic_json_view
```cpp
basic_json_view() noexcept = default;
```
Creates an invalid (discarded) view: [`type()`](type.md) is `#!cpp value_t::discarded`,
[`is_discarded()`](is_discarded.md) is `#!cpp true`, and `#!cpp explicit operator bool()` is `#!cpp false`.
This is the only constructor a caller can use directly. Every other view is obtained from a
[`basic_json_document`](../basic_json_document/index.md), via [`root()`](../basic_json_document/root.md) or by
navigating into a container with [`operator[]`](operator[].md), [`at`](at.md), [`front`](front.md), [`back`](back.md),
[`find`](find.md), or iteration.
## Exception safety
No-throw guarantee: this constructor never throws exceptions.
## Complexity
Constant.
## Notes
`basic_json_view` is trivially copyable (it holds two pointers), so a default-constructed view can be used as a
placeholder for "no value yet" and later be assigned a real view.
## Examples
??? example
The example below shows the default constructor and that a `basic_json_view` is a small, copyable handle.
```cpp
--8<-- "examples/basic_json_view__basic_json_view.cpp"
```
Output:
```json
--8<-- "examples/basic_json_view__basic_json_view.output"
```
## See also
- [is_discarded](is_discarded.md) - return whether the view is invalid
- [operator bool](operator_bool.md) - return whether the view refers to a value
- [root](../basic_json_document/root.md) - the view of a document's root value
## Version history
- Added in version 3.13.0.
@@ -1,61 +0,0 @@
# <small>nlohmann::basic_json_view::</small>begin
```cpp
iterator begin() const noexcept;
```
Returns an iterator to the first element of an array, or the first member value of an object, in **document order**
-- the order the values appear in the source text, not sorted by key. A primitive value iterates as a range of one
element (itself); `#!json null` and a [discarded](is_discarded.md) view iterate as an empty range.
## Return value
Iterator to the first element.
## Exception safety
No-throw guarantee: this function never throws exceptions.
## Complexity
Constant.
## Notes
For an object, iteration visits **every** member, including all occurrences of a duplicate key -- unlike
[`operator[]`](operator[].md), [`at`](at.md), [`find`](find.md), [`contains`](contains.md), and [`count`](count.md),
which all resolve to the *first* member with a given key. See the
[Notes on duplicate keys](operator[].md#notes) of `operator[]`.
Because objects are iterated in document order rather than sorted by key, the order seen here can differ from what
iterating the [`materialize()`](materialize.md)d `BasicJsonType` value would produce: a `#!cpp basic_json` object
(`std::map`-backed by default) sorts its keys, while a view does not.
## Examples
??? example
The example below iterates a log record's members with `begin()`/[`end()`](end.md) and prints them in the order
they were written. Materializing the record into a `BasicJsonType` object and iterating that would instead print
the members sorted by key.
```cpp
--8<-- "examples/basic_json_view__begin.cpp"
```
Output:
```json
--8<-- "examples/basic_json_view__begin.output"
```
## See also
- [end](end.md) - returns an iterator to one past the last element
- [cbegin](cbegin.md) - returns a const iterator to the first element
- [items](items.md) - access iterator member functions in range-based for
- [`BasicJsonType::begin`](../basic_json/begin.md) - the corresponding function of `basic_json`
## Version history
- Added in version 3.13.0.
@@ -1,49 +0,0 @@
# <small>nlohmann::basic_json_view::</small>cbegin
```cpp
iterator cbegin() const noexcept;
```
Returns an iterator to the first element, in [document order](begin.md). Equivalent to [`begin()`](begin.md): a view
is always read-only, so `#!cpp const_iterator` and `#!cpp iterator` are the same type, and `cbegin()` exists only so
that generic code that expects a `cbegin()`/`cend()` pair works with a view too.
## Return value
Iterator to the first element; identical to what [`begin()`](begin.md) returns.
## Exception safety
No-throw guarantee: this function never throws exceptions.
## Complexity
Constant.
## Examples
??? example
The example below sums many measurements with `std::accumulate`, using `cbegin()`/[`cend()`](cend.md) as the
range -- the same way it would for any standard container -- without ever materializing the whole array into a
`BasicJsonType` value.
```cpp
--8<-- "examples/basic_json_view__cbegin.cpp"
```
Output:
```json
--8<-- "examples/basic_json_view__cbegin.output"
```
## See also
- [begin](begin.md) - returns an iterator to the first element
- [cend](cend.md) - returns a const iterator to one past the last element
- [`BasicJsonType::cbegin`](../basic_json/cbegin.md) - the corresponding function of `basic_json`
## Version history
- Added in version 3.13.0.
@@ -1,49 +0,0 @@
# <small>nlohmann::basic_json_view::</small>cend
```cpp
iterator cend() const noexcept;
```
Returns an iterator to one past the last element, in [document order](begin.md). Equivalent to [`end()`](end.md): a
view is always read-only, so `#!cpp const_iterator` and `#!cpp iterator` are the same type, and `cend()` exists only
so that generic code that expects a `cbegin()`/`cend()` pair works with a view too.
## Return value
Iterator one past the last element; identical to what [`end()`](end.md) returns.
## Exception safety
No-throw guarantee: this function never throws exceptions.
## Complexity
Constant.
## Examples
??? example
The example below checks that every record of a batch is an object with `std::all_of`, using
[`cbegin()`](cbegin.md)/`cend()` as the range -- the same way it would for any standard container -- before
materializing any record of the batch.
```cpp
--8<-- "examples/basic_json_view__cend.cpp"
```
Output:
```json
--8<-- "examples/basic_json_view__cend.output"
```
## See also
- [end](end.md) - returns an iterator to one past the last element
- [cbegin](cbegin.md) - returns a const iterator to the first element
- [`BasicJsonType::cend`](../basic_json/cend.md) - the corresponding function of `basic_json`
## Version history
- Added in version 3.13.0.
@@ -1,103 +0,0 @@
# <small>nlohmann::basic_json_view::</small>contains
```cpp
// (1)
bool contains(string_view_t key) const;
bool contains(const char* key) const;
bool contains(const string_t& key) const;
// (2)
bool contains(const json_pointer& ptr) const;
```
1. Checks whether the value is an object with a member with key `key`.
2. Checks whether a JSON pointer `ptr` can be resolved, starting at this value.
## Parameters
`key` (in)
: key value to check its existence
`ptr` (in)
: JSON pointer to check its existence
## Return value
1. `#!cpp true` if the value is an object and has a member with key `key`, `#!cpp false` otherwise
2. `#!cpp true` if `ptr` can be resolved to a value starting at this view, `#!cpp false` otherwise
## Exception safety
No-throw guarantee: this function never throws exceptions.
## Complexity
1. Linear in the number of members: as for [`ordered_json`](../ordered_json.md), members are compared one after
another, in document order, stopping at the first match. Each comparison first checks the key's length -- already
known from the index, without reading the key bytes -- before comparing its content.
Objects with 128 or more members get a hash index while parsing, so that a lookup in them takes constant time
on average.
2. Linear in the number of reference tokens of `ptr` and, for each token, in the number of members of the object at
that level or the index into the array -- as for [`operator[]`](operator[].md#complexity) and
[`at`](at.md#complexity) with a JSON pointer.
## Notes
Overload 1 always returns `#!cpp false` when the value is not an object -- including a [discarded](is_discarded.md)
view.
!!! info "Postconditions"
If `#!cpp v.contains(key)` returns `#!cpp true`, then `#!cpp v[key]` is not [discarded](is_discarded.md). If
`#!cpp v.contains(ptr)` returns `#!cpp true`, then `#!cpp v[ptr]` is not discarded and `#!cpp v.at(ptr)` does not
throw.
!!! info "Overload 2 never throws"
Unlike [`BasicJsonType::contains(const json_pointer&)`](../basic_json/contains.md), which can throw for certain
malformed pointers (for instance an empty array-index reference token), overload 2 never throws: a missing key,
an out-of-range or malformed array index, a `#!cpp "-"` index, or a reference token used on a primitive all
simply make it return `#!cpp false`.
## Examples
??? example "Example: (1) check with key"
The example below counts how many of a batch of records carry an optional `retry_of` field, using `contains()`
to check without ever materializing a single record of the batch.
```cpp
--8<-- "examples/basic_json_view__contains.cpp"
```
Output:
```json
--8<-- "examples/basic_json_view__contains.output"
```
??? example "Example: (2) check with JSON pointer"
The example below checks an optional, nested field with a JSON pointer, and shows two pointers that
`#!cpp contains()` resolves to `#!cpp false` without throwing.
```cpp
--8<-- "examples/basic_json_view__contains_json_pointer.cpp"
```
Output:
```json
--8<-- "examples/basic_json_view__contains_json_pointer.output"
```
## See also
- [find](find.md) - find a value in an object
- [count](count.md) - returns the number of occurrences of a key
- [at](at.md), [operator[]](operator[].md) - resolve a JSON pointer and throw, or return a discarded view
- [`BasicJsonType::contains`](../basic_json/contains.md) - the corresponding function of `basic_json`
## Version history
- Added in version 3.13.0.
@@ -1,68 +0,0 @@
# <small>nlohmann::basic_json_view::</small>count
```cpp
size_type count(string_view_t key) const;
size_type count(const char* key) const;
size_type count(const string_t& key) const;
```
Returns `#!cpp 1` if the value is an object with a member with key `key`, `#!cpp 0` otherwise.
## Parameters
`key` (in)
: key value of the element to count
## Return value
`#!cpp 1` if the value is an object and has a member with key `key`, `#!cpp 0` otherwise.
## Exception safety
No-throw guarantee: this function never throws exceptions.
## Complexity
Linear in the number of members: as for [`ordered_json`](../ordered_json.md), members are compared one after
another, in document order, stopping at the first match. Each comparison first checks the key's length -- already
known from the index, without reading the key bytes -- before comparing its content.
Objects with 128 or more members get a hash index while parsing, so that a lookup in them takes constant time on
average.
## Notes
This method always returns `#!cpp 0` when the value is not an object -- including a [discarded](is_discarded.md)
view.
Unlike [`BasicJsonType::count()`](../basic_json/count.md), whose return value can in principle exceed `#!cpp 1` for
an `ObjectType` that allows multiple entries per key, `count()` here never does: it is exactly
[`contains()`](contains.md) as `#!cpp 0`/`#!cpp 1`. This holds even if the source text has a duplicate key -- see the
[Notes on duplicate keys](operator[].md#notes) of `operator[]` -- because a `#!cpp count() > 1` result would require
counting every member with a matching key, not just finding the first one.
## Examples
??? example
The example below validates that every transaction of a batch carries a mandatory `amount` field, using
`count()` before deciding whether to materialize a transaction at all.
```cpp
--8<-- "examples/basic_json_view__count.cpp"
```
Output:
```json
--8<-- "examples/basic_json_view__count.output"
```
## See also
- [find](find.md) - find a value in an object
- [contains](contains.md) - checks whether a key exists
- [`BasicJsonType::count`](../basic_json/count.md) - the corresponding function of `basic_json`
## Version history
- Added in version 3.13.0.

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