Compare commits

..
Author SHA1 Message Date
Niels Lohmann 9196e92520 Merge branch 'develop' into claude/todo-191-plan-508110
Conflicts: none textual. Follow-up fixes for develop's changes:
- docs/mkdocs/docs/api/ordered_map/index.md: develop's new paragraph
  (#5609) was written for api/ordered_map.md; fixed its relative
  ordered_json.md link for the page's new location, plus two
  pre-existing links from an earlier merge (ordered_json.md,
  features/object_order.md)
- tools/api_checker/api_surface.json: regenerated with libclang 18.1.1
  on Linux (swap() noexcept now includes json_base_class_t; new
  integral-key contains/count/find/value overloads)

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-30 20:36:12 +02:00
Niels Lohmann 7d22d865dd Merge branch 'develop' into claude/todo-191-plan-508110
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-28 22:22:46 +02:00
Niels Lohmann 4c73319d3b Use one-line module docstrings in the API checker scripts
Codacy runs two docstring checkers with opposite rules for module
docstrings: with the summary on the first line it reported D213, with
the summary on the second line it reports D212. A one-line docstring
satisfies both. Keep the summary as the docstring and move the details
into a comment below it; nothing reads the module docstrings.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-28 18:42:34 +02:00
Niels Lohmann da5097abcd Restore the CI spelling of json_pointer's operator string_t in the API surface
The develop merge regenerated api_surface.json on macOS, whose libclang
spells the name of the deprecated conversion operator as
"operator nlohmann::json_pointer::string_t_helper<...>::type". CI's
pinned libclang 18.1.1 on Linux spells it
"operator typename string_t_helper<...>::type", so check_api_docs
reported the file as out of date. This restores CI's spelling, which is
byte-identical to the file CI regenerated.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-27 21:37:14 +02:00
Niels Lohmann 2319f6e6f9 Address Codacy findings in the API checker scripts
Put multi-line docstring summaries on their own line, as a single
sentence followed by a blank line (pydocstyle D205, D209, D213, D415).

Annotate the subprocess import and calls with nosec: they only run
fixed argument lists, never through a shell (Bandit B404, B603, B607).
Do the same for the three broad except clauses in extract_api.py,
which deliberately fall through to the next libclang candidate or skip
an unresolvable alias (Bandit B110, B112).

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-27 18:09:03 +02:00
Niels Lohmann 9a0d1c0c47 Merge branch 'develop' into claude/todo-191-plan-508110
Resolve the conflict in docs/mkdocs/docs/home/architecture.md by taking
develop's rewritten page and pointing its ordered_map links at the moved
api/ordered_map/index.md. Also update the ordered_map.md links develop
added in ordered_json.md, object_order.md, and template_parameters.md.

Regenerate api_surface.json for the new BON8 functions and the changed
comparison operator. Restrict the documented_non_public leak check to
@sa URLs into json.nlohmann.me: develop now uses @sa to link GitHub
issues from private members such as copy_structured, which is not a
documentation leak.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-27 18:07:00 +02:00
Niels Lohmann 1bbb5d400a Regenerate api_surface.json after merging develop
develop added JSON_HEDLEY_WARN_UNUSED_RESULT to a number of basic_json
members (#5520) and reworked operator<<'s output adapter, so the
committed API surface no longer matched what extract_api.py produces and
the "Check for uncommitted API surface changes" step failed.

This is the patch the workflow itself uploads for that purpose; the
changes are limited to recorded signatures plus the way libclang spells
json_pointer's conversion operator.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-15 10:06:55 +02:00
Niels Lohmann 08d18d5a82 Merge remote-tracking branch 'origin/develop' into HEAD 2026-09-14 21:26:29 +02:00
Niels LohmannandClaude Sonnet 5 a27065bd12 Regenerate api_surface.json after merging develop
develop gained iterator+sentinel support for accept()/parse()/sax_parse()/
from_cbor()/from_msgpack()/from_ubjson()/from_bjdata()/from_bson() (#5205)
since this branch was created, which check_api_docs.yml's drift check caught
immediately: GitHub's pull_request trigger checks out the PR-vs-base merge
commit, not the PR branch in isolation, so CI was comparing the committed
api_surface.json (generated before that upstream change existed) against a
fresh extraction of a json.hpp that already had it.

This superseded an earlier, incorrect diagnosis of the same symptom (a
JSON_HAS_RANGES cross-environment pin) -- that fix remains in place since it's
still a real, independent determinism improvement for three other
JSON_HAS_RANGES-gated locations in type_traits.hpp, but it wasn't the actual
cause of this particular mismatch: these new overloads turned out to be
unconditional (SFINAE-gated via can_compare_ne, not preprocessor-gated), so
no environment-detection difference was involved here at all.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-07-11 23:45:46 +02:00
Niels Lohmann 3940f4b730 Merge remote-tracking branch 'origin/develop' into claude/todo-191-plan-508110 2026-07-11 23:43:30 +02:00
Niels LohmannandClaude Sonnet 5 0663907b68 Fix cross-environment API-surface drift and lint findings from CI
extract_api.py's own extraction wasn't deterministic across machines, which
CI's drift check caught immediately: JSON_HAS_RANGES auto-detects via the
standard library's __cpp_lib_ranges feature-test macro, which isn't reliably
gated to C++20 mode by every stdlib -- undefined under -std=c++17 with macOS's
libc++, but defined under the identical flag with the Ubuntu stdlib CI uses,
so parse()/accept()/from_*() extracted different signatures purely depending
on which machine ran the extraction. Pinned to -DJSON_HAS_RANGES=0: the
deterministic and safe choice, since pinning to 1 was tried first and found to
fail to parse on a stdlib without full <ranges> support even when the macro
claims otherwise.

Also found and fixed a second, independent source of the same class of drift:
get_identity_name() used cursor.spelling verbatim for CONVERSION_FUNCTION
cursors, which libclang renders as its own internally-canonicalized form of
the return type rather than what's literally written. Confirmed for
json_pointer::operator string_t() spelling differently on two machines
pinned to the identical libclang==18.1.1 wheel, with the JSON_HAS_RANGES fix
above ruled out as the cause. Now derived from the cursor's own raw source
text instead, immune to libclang's dependent-type resolution differences and
incidentally more readable than the libclang-internal forms it replaces.

Bumped SURFACE_FORMAT_VERSION to 3 and regenerated all 27 history snapshots
and the committed api_surface.json; both fixes are documented in
tools/api_checker/history/README.md's format-history log.

Also fixes diff_api.py's format_version guard, which only compared the two
loaded surfaces against each other and never against SURFACE_FORMAT_VERSION
(what this build actually understands) -- two surfaces on the same,
newer-than-expected format_version would have silently passed the guard.

Remaining fixes are the concretely actionable findings from Codacy's review
of the new tools/api_checker/ files: unused imports/variables, a stray
f-string with no placeholders. Left the docstring-formatting nitpicks
(pydocstyle D2xx/D4xx) and generic subprocess-usage notices alone -- the
former has no established convention elsewhere in this codebase's Python
tooling to conform to, and the latter are inherent to a dev tool that shells
out to git/clang with developer-controlled arguments, not user input.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-07-11 18:59:19 +02:00
Niels LohmannandClaude Sonnet 5 f23b3c63a2 Add AST-based public API checker and fix documentation gaps it found (#3691)
Adds tools/api_checker/: extract_api.py derives the public API surface directly
from the libclang AST (independent of documentation status), check_docs.py flags
public entries missing @sa links (and @sa on non-public ones), diff_api.py does
an overload-aware breaking/feature diff between two refs, check_macros.py cross-
checks documented macros against #define sites, and snapshot_release.py backfills
immutable per-release surface snapshots into tools/api_checker/history/ (v3.1.0
through v3.12.0) so diff_api.py can compare releases without live extraction.
POLICY.md documents what counts as public API and what stability is guaranteed.

Running this tooling against the current tree found and fixed a real documentation
backlog: ~25 new API doc pages (ordered_map's methods, json_sax's ctor/dtor/
operator=, byte_container_with_subtype's comparison operators, several orphaned
type aliases), each with a compiled and output-verified example, plus missing
@sa comments and stale/incorrect Version History entries on several existing
pages (found by diffing consecutive release pairs and checking whether the
resulting change was actually reflected in the target page's history section).

Also adds docs/home/api_changes.md, a per-release, per-function reference of
public API changes (v3.1.0 through v3.12.0) generated from the history/
snapshots, complementing (not replacing) the existing release notes.

Along the way, found and fixed several extractor bugs by testing against real
release tags rather than trusting the algorithm in isolation -- most notably an
identity-key scheme based on libclang's USR that encoded the enclosing class
template's own arity, and a since-renamed ABI inline-namespace pattern
(json_v3_11_0 vs. today's json_abi_v3_11_2) that neither of two earlier regex
attempts stripped correctly. Both are documented in extract_api.py's docstrings
and tools/api_checker/history/README.md so the failure mode doesn't recur
silently.

.github/workflows/check_api_docs.yml runs extract_api.py + check_docs.py in CI,
advisory-only for now (documented backlog may not be at zero for entities this
PR didn't touch), plus a blocking drift check on the committed
tools/api_checker/api_surface.json.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-07-11 18:59:00 +02:00
271 changed files with 73402 additions and 12611 deletions
-17
View File
@@ -45,23 +45,6 @@ labels:
- 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\\.cpp"
- "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_(document|view)\\.md"
- "docs/mkdocs/docs/examples/(basic_json_(document|view)__|(ordered_)?json_(document|view)).*"
- "tests/benchmarks/src/benchmarks_view\\.cpp"
- label: "aspect: json_view"
title: "(?i)(json_view|json_document|zero-copy)"
- label: "python"
files:
- "\\.py$"
+1 -4
View File
@@ -68,15 +68,12 @@ 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 .
cp include/nlohmann/json_literals.hpp $INCLUDE_DIR/json_literals.hpp
# the configuration of json_view.hpp comes with the pull request until
# it is on develop; the tool itself is still develop's
python3 $TOOL_DIR/amalgamate.py -c $MAIN_DIR/tools/amalgamate/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
+81
View File
@@ -0,0 +1,81 @@
name: "Check API documentation"
on:
pull_request:
permissions:
contents: read
jobs:
check_api_docs:
runs-on: ubuntu-latest
steps:
- name: Harden Runner
uses: step-security/harden-runner@bf7454d06d71f1098171f2acdf0cd4708d7b5920 # v2.20.0
with:
egress-policy: audit
- name: Checkout pull request
uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
- name: Install clang
# Used only as a subprocess for `clang++ -E -v` system-include-path discovery in
# extract_api.py; it does not need to version-match the pinned libclang pip wheel
# below, which does the actual AST parsing. Do not "fix" this to be version-matched.
run: sudo apt-get update && sudo apt-get install -y clang
- name: Install Python dependencies
run: pip install -r tools/api_checker/requirements.txt
- name: Extract API and regenerate the committed surface file
run: |
python3 tools/api_checker/extract_api.py \
--header include/nlohmann/json.hpp \
--include include \
--output /tmp/api_snapshot.json \
--surface-output tools/api_checker/api_surface.json
- name: "Check API documentation (Phase 1: advisory)"
# Surfaces missing/broken @sa links without failing the job while the backlog from the
# initial AST-based rollout is burned down. See tools/api_checker/POLICY.md and the PR
# that introduced this workflow for the two-phase rollout plan.
continue-on-error: true
run: |
python3 tools/api_checker/check_docs.py \
--snapshot /tmp/api_snapshot.json
- name: Check macro documentation (advisory only)
# Cross-checks docs/mkdocs/docs/api/macros/ pages against #define sites. Only checks the
# documented-macro-still-exists direction; never blocks CI. See POLICY.md.
run: python3 tools/api_checker/check_macros.py
- name: Check for uncommitted API surface changes
id: diff
run: |
mkdir -p ${{ github.workspace }}/patch
git diff --patch --no-color -- tools/api_checker/api_surface.json > ${{ github.workspace }}/patch/api_surface.patch
if [ -s ${{ github.workspace }}/patch/api_surface.patch ]; then
echo "tools/api_checker/api_surface.json is out of date. Diff:"
cat ${{ github.workspace }}/patch/api_surface.patch
echo "has_diff=true" >> "$GITHUB_OUTPUT"
else
echo "has_diff=false" >> "$GITHUB_OUTPUT"
fi
# Uploaded so contributors can fix their PR with `git apply api_surface.patch`
# instead of installing libclang locally.
- name: Upload patch
if: steps.diff.outputs.has_diff == 'true'
uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
with:
name: api-surface-patch
path: patch/api_surface.patch
- name: Fail if API surface file is not up to date
# Unlike the doc-backlog check above, this is purely mechanical regeneration with no
# backlog to phase in -- blocking from the start, matching check_amalgamation.yml's
# precedent. Contributors who add/remove/rename public API must regenerate and commit
# tools/api_checker/api_surface.json as part of their PR.
if: steps.diff.outputs.has_diff == 'true'
run: exit 1
+5
View File
@@ -3,6 +3,7 @@
*.gcno
*.gcda
.DS_Store
__pycache__/
/.idea
/cmake-build-*
@@ -43,5 +44,9 @@ venv
nlohmann_json.spdx
# api_checker: ephemeral, location/doc-status-sensitive working file (not the committed
# release-tracking artifact -- see tools/api_checker/api_surface.json for that)
/tools/api_checker/api_snapshot.json
# Bazel-related
MODULE.bazel.lock
-14
View File
@@ -20,7 +20,6 @@ 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",
@@ -66,21 +65,9 @@ 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/document_data.hpp",
"include/nlohmann/detail/view/errors.hpp",
"include/nlohmann/detail/view/input.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/scan.hpp",
"include/nlohmann/detail/view/string_ref.hpp",
"include/nlohmann/json.hpp",
"include/nlohmann/json_fwd.hpp",
"include/nlohmann/json_literals.hpp",
"include/nlohmann/json_view.hpp",
"include/nlohmann/ordered_map.hpp",
"include/nlohmann/thirdparty/hedley/hedley.hpp",
"include/nlohmann/thirdparty/hedley/hedley_undef.hpp",
@@ -93,7 +80,6 @@ cc_library(
name = "singleheader-json",
hdrs = [
"single_include/nlohmann/json.hpp",
"single_include/nlohmann/json_view.hpp",
],
includes = ["single_include"],
visibility = ["//visibility:public"],
+6 -25
View File
@@ -23,7 +23,6 @@ AMALGAMATED_FILE=single_include/nlohmann/json.hpp
AMALGAMATED_FWD_FILE=single_include/nlohmann/json_fwd.hpp
# json_literals.hpp only includes <nlohmann/json.hpp>, so it is copied verbatim
AMALGAMATED_LITERALS_FILE=single_include/nlohmann/json_literals.hpp
AMALGAMATED_VIEW_FILE=single_include/nlohmann/json_view.hpp
##########################################################################
@@ -32,7 +31,7 @@ AMALGAMATED_VIEW_FILE=single_include/nlohmann/json_view.hpp
# main target
all:
@echo "amalgamate - amalgamate files single_include/nlohmann/json{,_fwd,_literals,_view}.hpp from the include/nlohmann sources"
@echo "amalgamate - amalgamate files single_include/nlohmann/json{,_fwd,_literals}.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"
@@ -42,7 +41,6 @@ all:
@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"
@@ -100,14 +98,6 @@ 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
@@ -166,14 +156,14 @@ 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_LITERALS_FILE) $(AMALGAMATED_VIEW_FILE) docs/mkdocs/docs/examples/*.cpp
$(ASTYLE) --project=tools/astyle/.astylerc $(SRCS) $(TESTS_SRCS) $(AMALGAMATED_FILE) $(AMALGAMATED_FWD_FILE) $(AMALGAMATED_LITERALS_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_LITERALS_FILE) $(AMALGAMATED_VIEW_FILE)
amalgamate: $(AMALGAMATED_FILE) $(AMALGAMATED_FWD_FILE) $(AMALGAMATED_LITERALS_FILE)
$(MAKE) pretty
# call the amalgamation tool for json.hpp
@@ -188,26 +178,19 @@ $(AMALGAMATED_FWD_FILE): $(SRCS)
$(AMALGAMATED_LITERALS_FILE): include/nlohmann/json_literals.hpp
cp include/nlohmann/json_literals.hpp $(AMALGAMATED_LITERALS_FILE)
# 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_LITERALS_FILE) $(AMALGAMATED_LITERALS_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_LITERALS_FILE) $(AMALGAMATED_LITERALS_FILE)~ || (echo "===================================================================\n Amalgamation required! Please read the contribution guidelines\n in file .github/CONTRIBUTING.md.\n===================================================================" ; mv $(AMALGAMATED_LITERALS_FILE)~ $(AMALGAMATED_LITERALS_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_LITERALS_FILE)~ $(AMALGAMATED_LITERALS_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)
@@ -248,7 +231,7 @@ 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_LITERALS_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) $(AMALGAMATED_LITERALS_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
@@ -258,14 +241,12 @@ release: include.zip json.tar.xz
gpg --armor --detach-sig $(AMALGAMATED_FILE)
gpg --armor --detach-sig $(AMALGAMATED_FWD_FILE)
gpg --armor --detach-sig $(AMALGAMATED_LITERALS_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_LITERALS_FILE) release_files
cp $(AMALGAMATED_VIEW_FILE) release_files
mv $(AMALGAMATED_FILE).asc $(AMALGAMATED_FWD_FILE).asc $(AMALGAMATED_LITERALS_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 $(AMALGAMATED_LITERALS_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
##########################################################################
+2 -11
View File
@@ -106,7 +106,7 @@ Thanks everyone!
:books: If you want to **learn more** about how to use the library, check out the rest of the [**README**](#examples), have a look at [**code examples**](https://github.com/nlohmann/json/tree/develop/docs/mkdocs/docs/examples), or browse through the [**help pages**](https://json.nlohmann.me).
:construction: If you want to understand the **API** better, check out the [**API Reference**](https://json.nlohmann.me/api/basic_json/) or have a look at the [quick reference](#quick-reference) below.
:construction: If you want to understand the **API** better, check out the [**API Reference**](https://json.nlohmann.me/api/basic_json/) or have a look at the [quick reference](#quick-reference) below. The public API surface is derived mechanically and checked for documentation coverage by the tooling in [`tools/api_checker/`](tools/api_checker/), whose [POLICY.md](tools/api_checker/POLICY.md) defines what counts as public API and what stability is guaranteed.
:bug: If you found a **bug**, please check the [**FAQ**](https://json.nlohmann.me/home/faq/) if it is a known issue or the result of a design decision. Please also have a look at the [**issue list**](https://github.com/nlohmann/json/issues) before you [**create a new issue**](https://github.com/nlohmann/json/issues/new/choose). Please provide as much information as possible to help us understand and reproduce your issue.
@@ -1189,14 +1189,6 @@ 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).
@@ -1403,8 +1395,7 @@ 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, its table of powers of five, and its digit comparison for long numbers 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 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
<img align="right" src="https://git.fsfe.org/reuse/reuse-ci/raw/branch/master/reuse-horizontal.png" alt="REUSE Software">
+2 -5
View File
@@ -373,11 +373,10 @@ 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_literals.hpp~ ${include_dir}/json_view.hpp~
COMMAND rm -fr ${include_dir}/json.hpp~ ${include_dir}/json_fwd.hpp~ ${include_dir}/json_literals.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_literals.hpp ${include_dir}/json_literals.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
@@ -386,13 +385,11 @@ 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 cp ${PROJECT_SOURCE_DIR}/include/nlohmann/json_literals.hpp ${include_dir}/json_literals.hpp
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_literals.hpp~ ${include_dir}/json_literals.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
-1
View File
@@ -48,7 +48,6 @@ cc_library(
name = "singleheader-json",
hdrs = [
"single_include/nlohmann/json.hpp",
"single_include/nlohmann/json_view.hpp",
],
includes = ["single_include"],
visibility = ["//visibility:public"],
-39
View File
@@ -128,43 +128,7 @@ INSERT INTO searchIndex(name, type, path) VALUES ('basic_json::to_ubjson', 'Func
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::is_discarded', 'Method', 'api/basic_json_document/is_discarded/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::read', 'Method', 'api/basic_json_document/read/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_document::root', 'Method', 'api/basic_json_document/root/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_document::shrink_to_fit', 'Method', 'api/basic_json_document/shrink_to_fit/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_document::source', 'Method', 'api/basic_json_document/source/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_view', 'Class', 'api/basic_json_view/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_view::basic_json_view', 'Constructor', 'api/basic_json_view/basic_json_view/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_view::empty', 'Method', 'api/basic_json_view/empty/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_view::is_array', 'Method', 'api/basic_json_view/is_array/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_view::is_binary', 'Method', 'api/basic_json_view/is_binary/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_view::is_boolean', 'Method', 'api/basic_json_view/is_boolean/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_view::is_discarded', 'Method', 'api/basic_json_view/is_discarded/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_view::is_null', 'Method', 'api/basic_json_view/is_null/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_view::is_number', 'Method', 'api/basic_json_view/is_number/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_view::is_number_float', 'Method', 'api/basic_json_view/is_number_float/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_view::is_number_integer', 'Method', 'api/basic_json_view/is_number_integer/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_view::is_number_unsigned', 'Method', 'api/basic_json_view/is_number_unsigned/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_view::is_object', 'Method', 'api/basic_json_view/is_object/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_view::is_primitive', 'Method', 'api/basic_json_view/is_primitive/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_view::is_string', 'Method', 'api/basic_json_view/is_string/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_view::is_structured', 'Method', 'api/basic_json_view/is_structured/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_view::materialize', 'Method', 'api/basic_json_view/materialize/index.html');
INSERT INTO searchIndex(name, type, path) VALUES ('basic_json_view::operator bool', 'Method', 'api/basic_json_view/operator_bool/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 ('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_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');
@@ -198,8 +162,6 @@ 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_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');
@@ -229,7 +191,6 @@ 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');
@@ -420,7 +420,9 @@ basic_json(basic_json&& other) noexcept;
1. Since version 1.0.0.
2. Since version 1.0.0.
3. Since version 2.1.0.
4. Since version 3.2.0.
4. Since version 3.2.0. Also initializes the position reported by
[`start_pos()`](start_pos.md)/[`end_pos()`](end_pos.md) from `val` when
[`JSON_DIAGNOSTIC_POSITIONS`](../macros/json_diagnostic_positions.md) is enabled, since version 3.12.0.
5. Since version 1.0.0.
6. Since version 1.0.0.
7. Since version 1.0.0. Fixed in version 3.13.0 to also check the iterator range for binary values; before, a range
@@ -0,0 +1,38 @@
# <small>nlohmann::basic_json::</small>bjdata_version_t
```cpp
enum class bjdata_version_t
{
draft2,
draft3,
};
```
This enumeration is used in the [`to_bjdata`](to_bjdata.md) function to choose which draft version of
the BJData specification to encode ND-array extensions for:
draft2
: encode using the BJData Draft 2 ND-array format
draft3
: encode using the BJData Draft 3 ND-array format
## Examples
??? example
The example shows how `bjdata_version_t` selects the BJData draft used by `to_bjdata`.
```cpp
--8<-- "examples/bjdata_version_t.cpp"
```
Output:
```
--8<-- "examples/bjdata_version_t.output"
```
## Version history
- Added in version 3.12.0.
-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.
@@ -0,0 +1,32 @@
# <small>nlohmann::basic_json::</small>initializer_list_t
```cpp
using initializer_list_t = std::initializer_list<detail::json_ref<basic_json>>;
```
The type used for the initializer-list [constructor](basic_json.md) (overload 5) and for functions
such as [`operator=`](operator=.md) that accept a braced-init-list of JSON values. Each element wraps a
`basic_json` value or something convertible to one, deferring the decision of whether the list should be
parsed as a JSON array or a JSON object to the constructor itself.
See the [constructor](basic_json.md) documentation for how `initializer_list_t` values are interpreted.
## Examples
??? example
The example shows how an `initializer_list_t` is used to construct a JSON value.
```cpp
--8<-- "examples/initializer_list_t.cpp"
```
Output:
```
--8<-- "examples/initializer_list_t.output"
```
## Version history
- Since version 1.0.0.
@@ -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
@@ -0,0 +1,31 @@
# <small>nlohmann::basic_json::</small>json_sax_t
```cpp
using json_sax_t = json_sax<basic_json>;
```
The [`json_sax`](../json_sax/index.md) interface bound to this `basic_json` specialization, i.e. with
`BasicJsonType` fixed to `basic_json`. Used as the SAX interface type by [`sax_parse`](sax_parse.md) and
other SAX-based parsing functions.
See [`nlohmann::json_sax`](../json_sax/index.md) for more information.
## Examples
??? example
The example shows the type `json_sax_t`.
```cpp
--8<-- "examples/json_sax_t.cpp"
```
Output:
```
--8<-- "examples/json_sax_t.output"
```
## Version history
- Added in version 3.2.0.
@@ -23,10 +23,9 @@ type to use.
## Template parameters
`NumberFloatType`
: the type to store floating-point numbers. The parser converts `#!cpp float`, `#!cpp double`, and a
`#!cpp long double` that is IEEE 754 binary64 itself and other `#!cpp long double` formats with
`#!cpp std::from_chars` or `#!cpp std::strtold`, and serialization falls back to `#!cpp std::snprintf`, so the
type must be `#!cpp float`, `#!cpp double`, or `#!cpp long double`. The
: the type to store floating-point numbers. Parsing and serialization are implemented in terms of
`#!cpp std::strtof`/`#!cpp std::strtod`/`#!cpp std::strtold` and `#!cpp std::snprintf`, so the type must be
`#!cpp float`, `#!cpp double`, or `#!cpp long double`. The
[binary formats](../../features/binary_formats/index.md) additionally require `#!cpp float` or `#!cpp double`,
because they have no encoding for `#!cpp long double`. See
[Template Parameter Requirements](../../features/types/template_parameters.md#numberfloattype).
@@ -51,3 +51,5 @@ Linear.
## Version history
- Added in version 1.0.0.
- The `noexcept` specification was extended to also depend on
[`json_base_class_t`](json_base_class_t.md)'s move-assignment in version 3.11.3.
@@ -85,3 +85,8 @@ Linear in the size of the JSON value.
- Since version 1.0.0.
- Macros `JSON_EXPLICIT`/[`JSON_USE_IMPLICIT_CONVERSIONS`](../macros/json_use_implicit_conversions.md) added
in version 3.9.0.
- The exclusion of `std::any` from this conversion became conditional on
[`JSON_HAS_STATIC_RTTI`](../macros/json_has_static_rtti.md) in version 3.11.3.
- `std::optional<T>` excluded from this conversion in version 3.13.0; use
[`get<std::optional<T>>()`](get.md)/[`get_to()`](get_to.md) instead (see
[Converting values](../../features/conversions.md)).
-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.
-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.
@@ -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.
@@ -1,56 +0,0 @@
# <small>nlohmann::</small>basic_json_document
<small>Defined in header `<nlohmann/json_view.hpp>`</small>
```cpp
template<typename BasicJsonType>
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.
## 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`.
## Specializations
- [**json_document**](../json_document.md) - documents of the default specialization [`json`](../json.md)
- [**ordered_json_document**](../ordered_json_document.md) - 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>`)
- **value_t** - the JSON type enumeration, see [`basic_json::value_t`](../basic_json/value_t.md)
## Member functions
- [(constructor)](basic_json_document.md)
- [**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
- [**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
## 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.
@@ -1,50 +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.
@@ -1,139 +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
- [`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.
@@ -1,76 +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
## 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.
@@ -1,58 +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.
@@ -1,51 +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 (once
element access is added) from navigating into a container.
## 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>empty
```cpp
bool empty() const noexcept;
```
Checks whether [`size()`](size.md) is `0`, as [`BasicJsonType::empty()`](../basic_json/empty.md) would for the same
value.
## Return value
The return value depends on the type and is defined as follows:
| Value type | return value |
|----------------------|-----------------|
| null | `#!cpp true` |
| discarded | `#!cpp true` |
| boolean | `#!cpp false` |
| string | `#!cpp false` |
| number | `#!cpp false` |
| object | `#!cpp object_t::empty()` |
| array | `#!cpp array_t::empty()` |
## Exception safety
No-throw guarantee: this function never throws exceptions.
## Complexity
Constant.
## Notes
As for [`BasicJsonType::empty()`](../basic_json/empty.md), this does not return whether a string value is empty -- it
is `#!cpp false` for any string, regardless of its length.
## Examples
??? example
The example below uses [`size()`](size.md) and `empty()` to decide whether a parsed message is worth acting on,
without materializing it into a `BasicJsonType` value.
```cpp
--8<-- "examples/basic_json_view__size_empty.cpp"
```
Output:
```json
--8<-- "examples/basic_json_view__size_empty.output"
```
## See also
- [size](size.md) - return the number of elements
- [`BasicJsonType::empty`](../basic_json/empty.md) - the corresponding function of `basic_json`
## Version history
- Added in version 3.13.0.
@@ -1,82 +0,0 @@
# <small>nlohmann::</small>basic_json_view
<small>Defined in header `<nlohmann/json_view.hpp>`</small>
```cpp
template<typename BasicJsonType>
class basic_json_view;
```
A read-only handle to one value of a [`basic_json_document`](../basic_json_document/index.md): two pointers (a pointer
to the document and a pointer into its index), trivially copyable. A view is valid as long as
- the document is alive,
- the document has not been re-parsed with [`read()`](../basic_json_document/read.md) (or
[`parse()`](../basic_json_document/parse.md) into it) or shrunk with
[`shrink_to_fit()`](../basic_json_document/shrink_to_fit.md) since the view was taken, and
- if the document borrows its source text, that text is still alive.
Moving the document itself does not invalidate its views: the index is heap-allocated independently of the
`basic_json_document` object.
`basic_json_view` provides the read-only part of the `BasicJsonType` interface: the type-inspection functions, and
[`materialize()`](materialize.md) to build the `BasicJsonType` value of a subtree on demand. It does not (yet) provide
element access, iteration, `get<T>()`, JSON Pointer support, `dump()`, or comparison.
## Template parameters
`BasicJsonType`
: a specialization of [`basic_json`](../basic_json/index.md), matching the
[`basic_json_document`](../basic_json_document/index.md) the view was taken from.
## Specializations
- [**json_view**](../json_view.md) - views of a [`json_document`](../json_document.md)
- [**ordered_json_view**](../ordered_json_view.md) - views of an [`ordered_json_document`](../ordered_json_document.md)
## Member types
- **value_t** - the JSON type enumeration, see [`basic_json::value_t`](../basic_json/value_t.md)
- **string_t**, **number_integer_t**, **number_unsigned_t**, **number_float_t**, **json_pointer** - the corresponding
member types of `BasicJsonType`
- **size_type** - `#!cpp std::size_t`
- **string_view_t** - `#!cpp std::string_view` on C++17 and newer, a minimal internal substitute otherwise
## Member functions
- [(constructor)](basic_json_view.md)
### Object inspection
- [**type**](type.md) - return the type of the value
- [**is_null**](is_null.md) - return whether the value is null
- [**is_boolean**](is_boolean.md) - return whether the value is a boolean
- [**is_number**](is_number.md) - return whether the value is a number
- [**is_number_integer**](is_number_integer.md) - return whether the value is an integer number
- [**is_number_unsigned**](is_number_unsigned.md) - return whether the value is an unsigned integer number
- [**is_number_float**](is_number_float.md) - return whether the value is a floating-point number
- [**is_string**](is_string.md) - return whether the value is a string
- [**is_array**](is_array.md) - return whether the value is an array
- [**is_object**](is_object.md) - return whether the value is an object
- [**is_binary**](is_binary.md) - return whether the value is a binary array (always `#!cpp false`)
- [**is_primitive**](is_primitive.md) - return whether the type is primitive
- [**is_structured**](is_structured.md) - return whether the type is structured
- [**is_discarded**](is_discarded.md) - return whether the view is invalid
- [**operator bool**](operator_bool.md) - return whether the view refers to a value
### Capacity
- [**size**](size.md) - return the number of elements
- [**empty**](empty.md) - return whether the value has no elements
### Conversion
- [**materialize**](materialize.md) - build the `BasicJsonType` value of this subtree
### Source access
- [**source_offset**](source_offset.md) - byte offset of this value in the document's source text
## Version history
- Added in version 3.13.0.
@@ -1,46 +0,0 @@
# <small>nlohmann::basic_json_view::</small>is_array
```cpp
bool is_array() const noexcept;
```
This function returns `#!cpp true` if and only if the value is an array.
## Return value
`#!cpp true` if the type is an array, `#!cpp false` otherwise.
## Exception safety
No-throw guarantee: this function never throws exceptions.
## Complexity
Constant.
## Examples
??? example
The example below classifies several parsed documents by the type of their root value, without materializing any
of them into a `BasicJsonType` value.
```cpp
--8<-- "examples/basic_json_view__type_predicates.cpp"
```
Output:
```json
--8<-- "examples/basic_json_view__type_predicates.output"
```
## See also
- [is_structured](is_structured.md) - return whether the type is structured
- [size](size.md), [empty](empty.md) - the number of elements, and whether there are none
- [`BasicJsonType::is_array`](../basic_json/is_array.md) - the corresponding function of `basic_json`
## Version history
- Added in version 3.13.0.
@@ -1,46 +0,0 @@
# <small>nlohmann::basic_json_view::</small>is_binary
```cpp
bool is_binary() const noexcept;
```
This function always returns `#!cpp false`: a JSON text has no binary values, so a view can never refer to one. The
function exists for interface parity with [`BasicJsonType::is_binary`](../basic_json/is_binary.md).
## Return value
`#!cpp false`, always.
## Exception safety
No-throw guarantee: this function never throws exceptions.
## Complexity
Constant.
## Examples
??? example
The example below classifies several parsed documents by the type of their root value, without materializing any
of them into a `BasicJsonType` value.
```cpp
--8<-- "examples/basic_json_view__type_predicates.cpp"
```
Output:
```json
--8<-- "examples/basic_json_view__type_predicates.output"
```
## See also
- [type](type.md) - return the type of the value
- [`BasicJsonType::is_binary`](../basic_json/is_binary.md) - the corresponding function of `basic_json`
## Version history
- Added in version 3.13.0.
@@ -1,45 +0,0 @@
# <small>nlohmann::basic_json_view::</small>is_boolean
```cpp
bool is_boolean() const noexcept;
```
This function returns `#!cpp true` if and only if the value is a boolean.
## Return value
`#!cpp true` if the type is a boolean, `#!cpp false` otherwise.
## Exception safety
No-throw guarantee: this function never throws exceptions.
## Complexity
Constant.
## Examples
??? example
The example below classifies several parsed documents by the type of their root value, without materializing any
of them into a `BasicJsonType` value.
```cpp
--8<-- "examples/basic_json_view__type_predicates.cpp"
```
Output:
```json
--8<-- "examples/basic_json_view__type_predicates.output"
```
## See also
- [type](type.md) - return the type of the value
- [`BasicJsonType::is_boolean`](../basic_json/is_boolean.md) - the corresponding function of `basic_json`
## Version history
- Added in version 3.13.0.
@@ -1,55 +0,0 @@
# <small>nlohmann::basic_json_view::</small>is_discarded
```cpp
bool is_discarded() const noexcept;
```
Returns whether this view is invalid, i.e. does not refer to a value. This is the case for a default-constructed
view (see [(constructor)](basic_json_view.md)), and for [`root()`](../basic_json_document/root.md) of a document
that is itself [discarded](../basic_json_document/is_discarded.md) -- in particular, the root of a failed
[`parse()`](../basic_json_document/parse.md) with `allow_exceptions` set to `#!cpp false`.
## Return value
`#!cpp true` if the view is discarded, `#!cpp false` otherwise.
## Exception safety
No-throw guarantee: this function never throws exceptions.
## Complexity
Constant.
## Notes
`#!cpp v.is_discarded()` and `#!cpp !static_cast<bool>(v)` are equivalent; use whichever reads better at the call
site.
## Examples
??? example
The example below classifies several parsed documents by the type of their root value, without materializing any
of them into a `BasicJsonType` value.
```cpp
--8<-- "examples/basic_json_view__type_predicates.cpp"
```
Output:
```json
--8<-- "examples/basic_json_view__type_predicates.output"
```
## See also
- [operator bool](operator_bool.md) - return whether the view refers to a value
- [(constructor)](basic_json_view.md) - the default constructor creates a discarded view
- [is_discarded (basic_json_document)](../basic_json_document/is_discarded.md) - return whether the last parse failed
- [`BasicJsonType::is_discarded`](../basic_json/is_discarded.md) - the corresponding function of `basic_json`
## Version history
- Added in version 3.13.0.
@@ -1,45 +0,0 @@
# <small>nlohmann::basic_json_view::</small>is_null
```cpp
bool is_null() const noexcept;
```
This function returns `#!cpp true` if and only if the value is `#!json null`.
## Return value
`#!cpp true` if the type is `#!json null`, `#!cpp false` otherwise.
## Exception safety
No-throw guarantee: this function never throws exceptions.
## Complexity
Constant.
## Examples
??? example
The example below classifies several parsed documents by the type of their root value, without materializing any
of them into a `BasicJsonType` value.
```cpp
--8<-- "examples/basic_json_view__type_predicates.cpp"
```
Output:
```json
--8<-- "examples/basic_json_view__type_predicates.output"
```
## See also
- [type](type.md) - return the type of the value
- [`BasicJsonType::is_null`](../basic_json/is_null.md) - the corresponding function of `basic_json`
## Version history
- Added in version 3.13.0.
@@ -1,47 +0,0 @@
# <small>nlohmann::basic_json_view::</small>is_number
```cpp
bool is_number() const noexcept;
```
This function returns `#!cpp true` if and only if the value is a number, i.e. an integer, unsigned integer, or floating-point value. It is defined as `#!cpp is_number_integer() || is_number_float()`.
## Return value
`#!cpp true` if the type is a number, `#!cpp false` otherwise.
## Exception safety
No-throw guarantee: this function never throws exceptions.
## Complexity
Constant.
## Examples
??? example
The example below classifies several parsed documents by the type of their root value, without materializing any
of them into a `BasicJsonType` value.
```cpp
--8<-- "examples/basic_json_view__type_predicates.cpp"
```
Output:
```json
--8<-- "examples/basic_json_view__type_predicates.output"
```
## See also
- [is_number_integer](is_number_integer.md) - return whether the value is an integer or unsigned integer number
- [is_number_unsigned](is_number_unsigned.md) - return whether the value is an unsigned integer number
- [is_number_float](is_number_float.md) - return whether the value is a floating-point number
- [`BasicJsonType::is_number`](../basic_json/is_number.md) - the corresponding function of `basic_json`
## Version history
- Added in version 3.13.0.
@@ -1,51 +0,0 @@
# <small>nlohmann::basic_json_view::</small>is_number_float
```cpp
bool is_number_float() const noexcept;
```
This function returns `#!cpp true` if and only if the value is a floating-point number.
## Return value
`#!cpp true` if the type is `#!cpp value_t::number_float`, `#!cpp false` otherwise.
## Exception safety
No-throw guarantee: this function never throws exceptions.
## Complexity
Constant.
## Notes
As for [`BasicJsonType::parse`](../basic_json/parse.md), an integer literal that does not fit into the 64-bit
integer type is classified as a floating-point number, so `is_number_float()` can be `#!cpp true` even for an
integer-looking token in the source text.
## Examples
??? example
The example below classifies several parsed documents by the type of their root value, without materializing any
of them into a `BasicJsonType` value.
```cpp
--8<-- "examples/basic_json_view__type_predicates.cpp"
```
Output:
```json
--8<-- "examples/basic_json_view__type_predicates.output"
```
## See also
- [is_number](is_number.md) - return whether the value is a number
- [`BasicJsonType::is_number_float`](../basic_json/is_number_float.md) - the corresponding function of `basic_json`
## Version history
- Added in version 3.13.0.
@@ -1,51 +0,0 @@
# <small>nlohmann::basic_json_view::</small>is_number_integer
```cpp
bool is_number_integer() const noexcept;
```
This function returns `#!cpp true` if and only if the value is an integer or unsigned integer number.
## Return value
`#!cpp true` if the type is `#!cpp value_t::number_integer` or `#!cpp value_t::number_unsigned`, `#!cpp false` otherwise.
## Exception safety
No-throw guarantee: this function never throws exceptions.
## Complexity
Constant.
## Notes
As for [`BasicJsonType::is_number_integer`](../basic_json/is_number_integer.md), this includes unsigned integer
values; use [`is_number_unsigned`](is_number_unsigned.md) to test for those specifically.
## Examples
??? example
The example below classifies several parsed documents by the type of their root value, without materializing any
of them into a `BasicJsonType` value.
```cpp
--8<-- "examples/basic_json_view__type_predicates.cpp"
```
Output:
```json
--8<-- "examples/basic_json_view__type_predicates.output"
```
## See also
- [is_number](is_number.md) - return whether the value is a number
- [is_number_unsigned](is_number_unsigned.md) - return whether the value is an unsigned integer number
- [`BasicJsonType::is_number_integer`](../basic_json/is_number_integer.md) - the corresponding function of `basic_json`
## Version history
- Added in version 3.13.0.
@@ -1,45 +0,0 @@
# <small>nlohmann::basic_json_view::</small>is_number_unsigned
```cpp
bool is_number_unsigned() const noexcept;
```
This function returns `#!cpp true` if and only if the value is an unsigned integer number.
## Return value
`#!cpp true` if the type is `#!cpp value_t::number_unsigned`, `#!cpp false` otherwise.
## Exception safety
No-throw guarantee: this function never throws exceptions.
## Complexity
Constant.
## Examples
??? example
The example below classifies several parsed documents by the type of their root value, without materializing any
of them into a `BasicJsonType` value.
```cpp
--8<-- "examples/basic_json_view__type_predicates.cpp"
```
Output:
```json
--8<-- "examples/basic_json_view__type_predicates.output"
```
## See also
- [is_number_integer](is_number_integer.md) - return whether the value is an integer or unsigned integer number
- [`BasicJsonType::is_number_unsigned`](../basic_json/is_number_unsigned.md) - the corresponding function of `basic_json`
## Version history
- Added in version 3.13.0.
@@ -1,46 +0,0 @@
# <small>nlohmann::basic_json_view::</small>is_object
```cpp
bool is_object() const noexcept;
```
This function returns `#!cpp true` if and only if the value is an object.
## Return value
`#!cpp true` if the type is an object, `#!cpp false` otherwise.
## Exception safety
No-throw guarantee: this function never throws exceptions.
## Complexity
Constant.
## Examples
??? example
The example below classifies several parsed documents by the type of their root value, without materializing any
of them into a `BasicJsonType` value.
```cpp
--8<-- "examples/basic_json_view__type_predicates.cpp"
```
Output:
```json
--8<-- "examples/basic_json_view__type_predicates.output"
```
## See also
- [is_structured](is_structured.md) - return whether the type is structured
- [size](size.md), [empty](empty.md) - the number of elements, and whether there are none
- [`BasicJsonType::is_object`](../basic_json/is_object.md) - the corresponding function of `basic_json`
## Version history
- Added in version 3.13.0.
@@ -1,46 +0,0 @@
# <small>nlohmann::basic_json_view::</small>is_primitive
```cpp
bool is_primitive() const noexcept;
```
This function returns `#!cpp true` if and only if the value is primitive, i.e. `#!json null`, a boolean, a number, or a string. It is defined as `#!cpp is_null() || is_string() || is_boolean() || is_number()`.
## Return value
`#!cpp true` if the type is primitive, `#!cpp false` otherwise.
## Exception safety
No-throw guarantee: this function never throws exceptions.
## Complexity
Constant.
## Examples
??? example
The example below classifies several parsed documents by the type of their root value, without materializing any
of them into a `BasicJsonType` value.
```cpp
--8<-- "examples/basic_json_view__type_predicates.cpp"
```
Output:
```json
--8<-- "examples/basic_json_view__type_predicates.output"
```
## See also
- [is_structured](is_structured.md) - return whether the type is structured (the complement of this function, for a
non-discarded view)
- [`BasicJsonType::is_primitive`](../basic_json/is_primitive.md) - the corresponding function of `basic_json`
## Version history
- Added in version 3.13.0.
@@ -1,45 +0,0 @@
# <small>nlohmann::basic_json_view::</small>is_string
```cpp
bool is_string() const noexcept;
```
This function returns `#!cpp true` if and only if the value is a string.
## Return value
`#!cpp true` if the type is a string, `#!cpp false` otherwise.
## Exception safety
No-throw guarantee: this function never throws exceptions.
## Complexity
Constant.
## Examples
??? example
The example below classifies several parsed documents by the type of their root value, without materializing any
of them into a `BasicJsonType` value.
```cpp
--8<-- "examples/basic_json_view__type_predicates.cpp"
```
Output:
```json
--8<-- "examples/basic_json_view__type_predicates.output"
```
## See also
- [source_offset](source_offset.md) - byte offset of this value in the document's source text
- [`BasicJsonType::is_string`](../basic_json/is_string.md) - the corresponding function of `basic_json`
## Version history
- Added in version 3.13.0.
@@ -1,46 +0,0 @@
# <small>nlohmann::basic_json_view::</small>is_structured
```cpp
bool is_structured() const noexcept;
```
This function returns `#!cpp true` if and only if the value is structured, i.e. an array or an object. It is defined as `#!cpp is_array() || is_object()`.
## Return value
`#!cpp true` if the type is structured, `#!cpp false` otherwise.
## Exception safety
No-throw guarantee: this function never throws exceptions.
## Complexity
Constant.
## Examples
??? example
The example below classifies several parsed documents by the type of their root value, without materializing any
of them into a `BasicJsonType` value.
```cpp
--8<-- "examples/basic_json_view__type_predicates.cpp"
```
Output:
```json
--8<-- "examples/basic_json_view__type_predicates.output"
```
## See also
- [is_primitive](is_primitive.md) - return whether the type is primitive
- [size](size.md), [empty](empty.md) - the number of elements, and whether there are none
- [`BasicJsonType::is_structured`](../basic_json/is_structured.md) - the corresponding function of `basic_json`
## Version history
- Added in version 3.13.0.
@@ -1,69 +0,0 @@
# <small>nlohmann::basic_json_view::</small>materialize
```cpp
BasicJsonType materialize() const;
```
Builds the `BasicJsonType` value of this subtree: the value [`BasicJsonType::parse()`](../basic_json/parse.md) would
have produced for the same source text, allocated for the first time by this call.
## Return value
The `BasicJsonType` value of this subtree, or a discarded `BasicJsonType` value (`#!cpp BasicJsonType(value_t::discarded)`)
if the view is [discarded](is_discarded.md).
## Exception safety
Strong guarantee: if an exception is thrown, there are no changes to the view or the document it refers to (nothing
about either is mutated by this function).
## Exceptions
May throw `#!cpp std::bad_alloc` (via `BasicJsonType`'s allocator) if constructing the result fails.
## Complexity
Linear in the size of the subtree.
## Notes
`materialize()` replays the subtree through the same SAX builder [`BasicJsonType::parse()`](../basic_json/parse.md)
uses internally, so the result matches it exactly -- including, for an object, that a repeated key keeps only its
last value. The replay is iterative, so it is not limited by the call stack the way a naive recursive conversion
would be; the JSON nesting depth is limited only by available memory, as for `BasicJsonType::parse()` itself.
Unlike parsing with [`JSON_DIAGNOSTIC_POSITIONS`](../macros/json_diagnostic_positions.md) enabled, the values
produced by `materialize()` do not carry source positions: there is no lexer run during the replay to record them.
Calling `materialize()` on the same view repeatedly builds a new, independent `BasicJsonType` value each time; it
never caches the result.
## Examples
??? example
The example below skips messages that are not useful -- a discarded value, or an empty array -- using only
[`is_array()`](is_array.md) and [`empty()`](empty.md), and calls `materialize()` only for the messages that are
actually used, so no `BasicJsonType` value (and none of its per-element allocations) is ever built for the
skipped ones.
```cpp
--8<-- "examples/basic_json_view__materialize.cpp"
```
Output:
```json
--8<-- "examples/basic_json_view__materialize.output"
```
## See also
- [root](../basic_json_document/root.md) - the view of a document's root value
- [`BasicJsonType::parse`](../basic_json/parse.md) - build a `BasicJsonType` value directly from a JSON text
- [`JSON_DIAGNOSTIC_POSITIONS`](../macros/json_diagnostic_positions.md) - source positions on parsed values (not
produced by `materialize()`)
## Version history
- Added in version 3.13.0.
@@ -1,46 +0,0 @@
# <small>nlohmann::basic_json_view::</small>operator bool
```cpp
explicit operator bool() const noexcept;
```
Returns whether this view refers to a value, i.e. the negation of [`is_discarded()`](is_discarded.md). Being
`#!cpp explicit`, this conversion is only considered in a boolean context (`#!cpp if (v)`, `#!cpp !v`, `#!cpp v &&
...`), not for implicit conversions to other types.
## Return value
`#!cpp true` if the view refers to a value, `#!cpp false` if it is [discarded](is_discarded.md).
## Exception safety
No-throw guarantee: this function never throws exceptions.
## Complexity
Constant.
## Examples
??? example
The example below classifies several parsed documents by the type of their root value, without materializing any
of them into a `BasicJsonType` value.
```cpp
--8<-- "examples/basic_json_view__type_predicates.cpp"
```
Output:
```json
--8<-- "examples/basic_json_view__type_predicates.output"
```
## See also
- [is_discarded](is_discarded.md) - return whether the view is invalid
## Version history
- Added in version 3.13.0.
@@ -1,60 +0,0 @@
# <small>nlohmann::basic_json_view::</small>size
```cpp
size_type size() const noexcept;
```
Returns the number of elements, as [`BasicJsonType::size()`](../basic_json/size.md) would for the same value.
## Return value
The return value depends on the type and is defined as follows:
| Value type | return value |
|----------------------|-----------------------------|
| null | `0` |
| discarded | `0` |
| boolean | `1` |
| string | `1` |
| number | `1` |
| object | number of key/value pairs |
| array | number of elements |
## Exception safety
No-throw guarantee: this function never throws exceptions.
## Complexity
Constant: for an object or array, the element count is stored in the index, not counted on demand.
## Notes
As for [`BasicJsonType::size()`](../basic_json/size.md), this does not return the length of a string value -- it is
`1` for a string, regardless of its length.
## Examples
??? example
The example below uses `size()` and [`empty()`](empty.md) to decide whether a parsed message is worth acting on,
without materializing it into a `BasicJsonType` value.
```cpp
--8<-- "examples/basic_json_view__size_empty.cpp"
```
Output:
```json
--8<-- "examples/basic_json_view__size_empty.output"
```
## See also
- [empty](empty.md) - return whether the value has no elements
- [`BasicJsonType::size`](../basic_json/size.md) - the corresponding function of `basic_json`
## Version history
- Added in version 3.13.0.
@@ -1,55 +0,0 @@
# <small>nlohmann::basic_json_view::</small>source_offset
```cpp
std::size_t source_offset() const noexcept;
```
Returns the byte offset of this value in the document's [`source()`](../basic_json_document/source.md) text, without
materializing anything.
## Return value
- For a string with no escapes, a number, `#!json true`/`#!json false`/`#!json null`, an array, or an object: the
byte offset of the first byte of the value's token (for a string: the first byte after the opening quote) in
[`source()`](../basic_json_document/source.md).
- `#!cpp static_cast<std::size_t>(-1)` for a [discarded](is_discarded.md) view, and for a string that contains
escapes -- such a string was decoded once into the document's own buffer, so there is no single byte range in
`source()` left to point at.
## Exception safety
No-throw guarantee: this function never throws exceptions.
## Complexity
Constant.
## Notes
This is a raw offset, not a length: the API does not (yet) expose how many bytes the token occupies in the source
text, so `source_offset()` alone is enough to report *where* a value came from (for an error message, for syntax
highlighting, ...) but not to slice its exact text back out of [`source()`](../basic_json_document/source.md) for a
string, whose token length is not the same as its decoded [`size()`](size.md).
## Examples
??? example
```cpp
--8<-- "examples/basic_json_view__source_offset.cpp"
```
Output:
```json
--8<-- "examples/basic_json_view__source_offset.output"
```
## See also
- [source](../basic_json_document/source.md) - the parsed text
- [is_string](is_string.md) - return whether the value is a string
## Version history
- Added in version 3.13.0.
@@ -1,53 +0,0 @@
# <small>nlohmann::basic_json_view::</small>type
```cpp
value_t type() const noexcept;
```
Returns the type of the value this view refers to, as a value from the [`value_t`](../basic_json/value_t.md)
enumeration -- the same enumeration [`BasicJsonType::type()`](../basic_json/type.md) uses.
## Return value
The type of the value; `#!cpp value_t::discarded` for a [discarded](is_discarded.md) view.
## Exception safety
No-throw guarantee: this function never throws exceptions.
## Complexity
Constant.
## Notes
Unlike [`BasicJsonType::type()`](../basic_json/type.md), this function can never return `#!cpp value_t::binary`: a
JSON text has no binary values, so `type()` only distinguishes the eight ordinary JSON value types (plus
`#!cpp discarded`).
## Examples
??? example
The example below classifies several parsed documents by the type of their root value, without materializing any
of them into a `BasicJsonType` value.
```cpp
--8<-- "examples/basic_json_view__type_predicates.cpp"
```
Output:
```json
--8<-- "examples/basic_json_view__type_predicates.output"
```
## See also
- [is_null](is_null.md), [is_boolean](is_boolean.md), [is_number](is_number.md), [is_string](is_string.md),
[is_array](is_array.md), [is_object](is_object.md) - type-specific predicates built on `type()`
- [`BasicJsonType::type`](../basic_json/type.md) - the corresponding function of `basic_json`
## Version history
- Added in version 3.13.0.
@@ -0,0 +1,32 @@
# <small>nlohmann::byte_container_with_subtype::</small>container_type
```cpp
using container_type = BinaryType;
```
The type of the underlying binary container, forwarded from the `BinaryType` template parameter that
`byte_container_with_subtype` is instantiated with. `byte_container_with_subtype` publicly inherits from
`container_type`.
See [`basic_json::binary_t`](../basic_json/binary_t.md) for the type typically used to instantiate
`BinaryType`.
## Examples
??? example
The example shows the type `container_type`.
```cpp
--8<-- "examples/byte_container_with_subtype__container_type.cpp"
```
Output:
```
--8<-- "examples/byte_container_with_subtype__container_type.output"
```
## Version history
- Since version 3.8.0.
@@ -0,0 +1,45 @@
# <small>nlohmann::byte_container_with_subtype::</small>operator==
```cpp
bool operator==(const byte_container_with_subtype& rhs) const;
```
Compares two `byte_container_with_subtype` values for equality by comparing the underlying binary
container, the subtype, and whether a subtype is set.
## Parameters
`rhs` (in)
: value to compare `*this` against
## Return value
whether `*this` and `rhs` are equal
## Exception safety
No-throw guarantee: this function never throws exceptions.
## Complexity
Linear in the size of the underlying binary container.
## Examples
??? example
The example demonstrates comparing `byte_container_with_subtype` values.
```cpp
--8<-- "examples/byte_container_with_subtype__operator_eq.cpp"
```
Output:
```
--8<-- "examples/byte_container_with_subtype__operator_eq.output"
```
## Version history
- Since version 3.8.0.
@@ -0,0 +1,45 @@
# <small>nlohmann::byte_container_with_subtype::</small>operator!=
```cpp
bool operator!=(const byte_container_with_subtype& rhs) const;
```
Compares two `byte_container_with_subtype` values for inequality. Implemented as the negation of
[`operator==`](operator_eq.md).
## Parameters
`rhs` (in)
: value to compare `*this` against
## Return value
whether `*this` and `rhs` are not equal
## Exception safety
No-throw guarantee: this function never throws exceptions.
## Complexity
Linear in the size of the underlying binary container.
## Examples
??? example
The example demonstrates comparing `byte_container_with_subtype` values.
```cpp
--8<-- "examples/byte_container_with_subtype__operator_ne.cpp"
```
Output:
```
--8<-- "examples/byte_container_with_subtype__operator_ne.output"
```
## Version history
- Since version 3.8.0.
@@ -0,0 +1,28 @@
# <small>nlohmann::byte_container_with_subtype::</small>subtype_type
```cpp
using subtype_type = std::uint64_t;
```
The type used to store the optional binary subtype tag. See [`subtype`](subtype.md) and
[`set_subtype`](set_subtype.md).
## Examples
??? example
The example shows the type `subtype_type`.
```cpp
--8<-- "examples/byte_container_with_subtype__subtype_type.cpp"
```
Output:
```
--8<-- "examples/byte_container_with_subtype__subtype_type.output"
```
## Version history
- Since version 3.8.0.
-35
View File
@@ -1,35 +0,0 @@
# <small>nlohmann::</small>json_document
<small>Defined in header `<nlohmann/json_view.hpp>`</small>
```cpp
using json_document = basic_json_document<json>;
```
This type is a [`basic_json_document`](basic_json_document/index.md) of the default [`json`](json.md)
specialization.
## Examples
??? example
The example below demonstrates how to use the type `nlohmann::json_document`.
```cpp
--8<-- "examples/json_document.cpp"
```
Output:
```json
--8<-- "examples/json_document.output"
```
## See also
- [json_view](json_view.md) - a view of a value of a `json_document`
- [ordered_json_document](ordered_json_document.md) - the corresponding document for `ordered_json`
## Version history
Since version 3.13.0.
+30
View File
@@ -0,0 +1,30 @@
# <small>nlohmann::json_sax::</small>binary_t
```cpp
using binary_t = typename BasicJsonType::binary_t;
```
The type used by the [`binary`](binary.md) callback for JSON binary values, forwarded from the
`BasicJsonType` template parameter.
See [`basic_json::binary_t`](../basic_json/binary_t.md) for more information.
## Examples
??? example
The example shows the type `binary_t` and its relation to `basic_json::binary_t`.
```cpp
--8<-- "examples/json_sax__binary_t.cpp"
```
Output:
```
--8<-- "examples/json_sax__binary_t.output"
```
## Version history
- Added in version 3.8.0.
+33
View File
@@ -0,0 +1,33 @@
# <small>nlohmann::json_sax::</small>json_sax
```cpp
// (1)
json_sax() = default;
// (2)
json_sax(const json_sax&) = default;
// (3)
json_sax(json_sax&&) noexcept = default;
```
1. Default constructor.
2. Copy constructor.
3. Move constructor.
`json_sax` is a pure abstract base class with no data members of its own, so all three constructors are
defaulted and only exist to make derived SAX consumers explicitly copyable/movable.
## Exception safety
No-throw guarantee: none of these constructors throw exceptions.
## Complexity
Constant.
<!-- NOLINT Examples -->
## Version history
- Added in version 3.2.0.
@@ -0,0 +1,30 @@
# <small>nlohmann::json_sax::</small>number_float_t
```cpp
using number_float_t = typename BasicJsonType::number_float_t;
```
The type used by the [`number_float`](number_float.md) callback for JSON floating-point numbers,
forwarded from the `BasicJsonType` template parameter.
See [`basic_json::number_float_t`](../basic_json/number_float_t.md) for more information.
## Examples
??? example
The example shows the type `number_float_t` and its relation to `basic_json::number_float_t`.
```cpp
--8<-- "examples/json_sax__number_float_t.cpp"
```
Output:
```
--8<-- "examples/json_sax__number_float_t.output"
```
## Version history
- Added in version 3.2.0.
@@ -0,0 +1,30 @@
# <small>nlohmann::json_sax::</small>number_integer_t
```cpp
using number_integer_t = typename BasicJsonType::number_integer_t;
```
The type used by the [`number_integer`](number_integer.md) callback for JSON integer numbers, forwarded
from the `BasicJsonType` template parameter.
See [`basic_json::number_integer_t`](../basic_json/number_integer_t.md) for more information.
## Examples
??? example
The example shows the type `number_integer_t` and its relation to `basic_json::number_integer_t`.
```cpp
--8<-- "examples/json_sax__number_integer_t.cpp"
```
Output:
```
--8<-- "examples/json_sax__number_integer_t.output"
```
## Version history
- Added in version 3.2.0.
@@ -0,0 +1,30 @@
# <small>nlohmann::json_sax::</small>number_unsigned_t
```cpp
using number_unsigned_t = typename BasicJsonType::number_unsigned_t;
```
The type used by the [`number_unsigned`](number_unsigned.md) callback for JSON unsigned integer numbers,
forwarded from the `BasicJsonType` template parameter.
See [`basic_json::number_unsigned_t`](../basic_json/number_unsigned_t.md) for more information.
## Examples
??? example
The example shows the type `number_unsigned_t` and its relation to `basic_json::number_unsigned_t`.
```cpp
--8<-- "examples/json_sax__number_unsigned_t.cpp"
```
Output:
```
--8<-- "examples/json_sax__number_unsigned_t.output"
```
## Version history
- Added in version 3.2.0.
@@ -0,0 +1,29 @@
# <small>nlohmann::json_sax::</small>operator=
```cpp
// (1)
json_sax& operator=(const json_sax&) = default;
// (2)
json_sax& operator=(json_sax&&) noexcept = default;
```
1. Copy assignment operator.
2. Move assignment operator.
`json_sax` is a pure abstract base class with no data members of its own, so both assignment operators
are defaulted and only exist to make derived SAX consumers explicitly copy-/move-assignable.
## Exception safety
No-throw guarantee: neither operator throws exceptions.
## Complexity
Constant.
<!-- NOLINT Examples -->
## Version history
- Added in version 3.2.0.
+30
View File
@@ -0,0 +1,30 @@
# <small>nlohmann::json_sax::</small>string_t
```cpp
using string_t = typename BasicJsonType::string_t;
```
The type used by the [`string`](string.md) and [`key`](key.md) callbacks for JSON strings and object
keys, forwarded from the `BasicJsonType` template parameter.
See [`basic_json::string_t`](../basic_json/string_t.md) for more information.
## Examples
??? example
The example shows the type `string_t` and its relation to `basic_json::string_t`.
```cpp
--8<-- "examples/json_sax__string_t.cpp"
```
Output:
```
--8<-- "examples/json_sax__string_t.output"
```
## Version history
- Added in version 3.2.0.
@@ -0,0 +1,22 @@
# <small>nlohmann::json_sax::</small>~json_sax
```cpp
virtual ~json_sax() = default;
```
Destructor. Virtual to allow proper destruction of derived SAX consumer classes through a
pointer/reference to `json_sax`.
## Exception safety
No-throw guarantee: this destructor never throws exceptions.
## Complexity
Constant.
<!-- NOLINT Examples -->
## Version history
- Added in version 3.2.0.
-34
View File
@@ -1,34 +0,0 @@
# <small>nlohmann::</small>json_view
<small>Defined in header `<nlohmann/json_view.hpp>`</small>
```cpp
using json_view = basic_json_view<json>;
```
This type is a [`basic_json_view`](basic_json_view/index.md) of a value of a [`json_document`](json_document.md).
## Examples
??? example
The example below demonstrates how to use the type `nlohmann::json_view`.
```cpp
--8<-- "examples/json_view.cpp"
```
Output:
```json
--8<-- "examples/json_view.output"
```
## See also
- [json_document](json_document.md) - the document type this view refers into
- [ordered_json_view](ordered_json_view.md) - the corresponding view for `ordered_json_document`
## Version history
Since version 3.13.0.
+4 -4
View File
@@ -8,16 +8,16 @@ This type preserves the insertion order of object keys.
## Iterator invalidation
The type is based on [`ordered_map`](ordered_map.md) which in turn uses a `std::vector` to store object elements.
The type is based on [`ordered_map`](ordered_map/index.md) which in turn uses a `std::vector` to store object elements.
Therefore, adding object elements can yield a reallocation in which case all iterators (including the
[`end()`](basic_json/end.md) iterator) and all references to the elements are invalidated. Also, any iterator or
reference after the insertion point will point to the same index, which is now a different value.
## Complexity
[`ordered_map`](ordered_map.md) has no lookup index: every key-based object operation is a linear scan, so building or
[`ordered_map`](ordered_map/index.md) has no lookup index: every key-based object operation is a linear scan, so building or
parsing an object of `n` keys costs O(n²) rather than O(n log n). See
[`ordered_map` complexity](ordered_map.md#complexity) for the per-operation table and for measured numbers.
[`ordered_map` complexity](ordered_map/index.md#complexity) for the per-operation table and for measured numbers.
## Examples
@@ -37,7 +37,7 @@ parsing an object of `n` keys costs O(n²) rather than O(n log n). See
## See also
- [ordered_map](ordered_map.md)
- [ordered_map](ordered_map/index.md)
- [Object Order](../features/object_order.md)
## Version history
@@ -1,38 +0,0 @@
# <small>nlohmann::</small>ordered_json_document
<small>Defined in header `<nlohmann/json_view.hpp>`</small>
```cpp
using ordered_json_document = basic_json_document<ordered_json>;
```
This type is a [`basic_json_document`](basic_json_document/index.md) of the [`ordered_json`](ordered_json.md)
specialization: [`materialize()`](basic_json_view/materialize.md) on one of its views preserves the insertion order
of object keys, instead of sorting them like [`json_document`](json_document.md) does.
## Examples
??? example
The example below demonstrates how `ordered_json_document` preserves the insertion order of object keys when
materializing.
```cpp
--8<-- "examples/ordered_json_document.cpp"
```
Output:
```json
--8<-- "examples/ordered_json_document.output"
```
## See also
- [ordered_json_view](ordered_json_view.md) - a view of a value of an `ordered_json_document`
- [json_document](json_document.md) - the corresponding document for the default `json` specialization
- [Object Order](../features/object_order.md)
## Version history
Since version 3.13.0.
-35
View File
@@ -1,35 +0,0 @@
# <small>nlohmann::</small>ordered_json_view
<small>Defined in header `<nlohmann/json_view.hpp>`</small>
```cpp
using ordered_json_view = basic_json_view<ordered_json>;
```
This type is a [`basic_json_view`](basic_json_view/index.md) of a value of an
[`ordered_json_document`](ordered_json_document.md).
## Examples
??? example
The example below demonstrates how to use the type `nlohmann::ordered_json_view`.
```cpp
--8<-- "examples/ordered_json_view.cpp"
```
Output:
```json
--8<-- "examples/ordered_json_view.output"
```
## See also
- [ordered_json_document](ordered_json_document.md) - the document type this view refers into
- [json_view](json_view.md) - the corresponding view for `json_document`
## Version history
Since version 3.13.0.
@@ -0,0 +1,28 @@
# <small>nlohmann::ordered_map::</small>Container
```cpp
using Container = std::vector<std::pair<const Key, T>, Allocator>;
```
The base container type that `ordered_map` publicly inherits from. Elements are stored in insertion
order as `#!cpp std::pair<const Key, T>` entries in a `std::vector`.
## Examples
??? example
The example shows the type `Container`.
```cpp
--8<-- "examples/ordered_map__Container.cpp"
```
Output:
```
--8<-- "examples/ordered_map__Container.output"
```
## Version history
- Added in version 3.9.0 to implement [`nlohmann::ordered_json`](../ordered_json.md).
+61
View File
@@ -0,0 +1,61 @@
# <small>nlohmann::ordered_map::</small>at
```cpp
// (1)
T& at(const key_type& key);
const T& at(const key_type& key) const;
// (2)
template<class KeyType>
T& at(KeyType&& key);
template<class KeyType>
const T& at(KeyType&& key) const;
```
1. Returns a reference to the value mapped to `key`.
2. Same as (1), but for any `KeyType` comparable to `key_type` via [`key_compare`](key_compare.md)
(heterogeneous lookup, e.g. looking up by a `#!cpp const char*` without constructing a temporary
`key_type`). Only participates in overload resolution if `KeyType` is usable as a key type.
## Template parameters
`KeyType`
: a type comparable to `key_type` via [`key_compare`](key_compare.md)
## Parameters
`key` (in)
: key of the element to find
## Return value
reference to the mapped value of the element with key equal to `key`
## Exceptions
Throws `std::out_of_range` if no element with key `key` exists.
## Complexity
Linear in the number of elements.
## Examples
??? example
The example shows how `at` is used.
```cpp
--8<-- "examples/ordered_map__at.cpp"
```
Output:
```
--8<-- "examples/ordered_map__at.output"
```
## Version history
- Added in version 3.9.1 to implement [`nlohmann::ordered_json`](../ordered_json.md).
- Overload (2) added in version 3.11.0.
+53
View File
@@ -0,0 +1,53 @@
# <small>nlohmann::ordered_map::</small>count
```cpp
// (1)
size_type count(const key_type& key) const;
// (2)
template<class KeyType>
size_type count(KeyType&& key) const;
```
1. Returns the number of elements with key equal to `key` (0 or 1, since keys are unique).
2. Same as (1), but for any `KeyType` comparable to `key_type` via [`key_compare`](key_compare.md)
(heterogeneous lookup). Only participates in overload resolution if `KeyType` is usable as a key type.
## Template parameters
`KeyType`
: a type comparable to `key_type` via [`key_compare`](key_compare.md)
## Parameters
`key` (in)
: key of the elements to count
## Return value
number of elements with key equal to `key` (0 or 1)
## Complexity
Linear in the number of elements.
## Examples
??? example
The example shows how `count` is used.
```cpp
--8<-- "examples/ordered_map__count.cpp"
```
Output:
```
--8<-- "examples/ordered_map__count.output"
```
## Version history
- Added in version 3.9.1 to implement [`nlohmann::ordered_json`](../ordered_json.md).
- Overload (2) added in version 3.11.0.
@@ -0,0 +1,58 @@
# <small>nlohmann::ordered_map::</small>emplace
```cpp
// (1)
std::pair<iterator, bool> emplace(const key_type& key, T&& t);
// (2)
template<class KeyType>
std::pair<iterator, bool> emplace(KeyType&& key, T&& t);
```
1. Inserts `#!cpp {key, t}` if no element with an equal key already exists (per [`key_compare`](key_compare.md)),
appending it at the end to preserve insertion order. If an equal key already exists, does nothing.
2. Same as (1), but for any `KeyType` comparable to `key_type` via [`key_compare`](key_compare.md)
(heterogeneous lookup). Only participates in overload resolution if `KeyType` is usable as a key type.
## Template parameters
`KeyType`
: a type comparable to `key_type` via [`key_compare`](key_compare.md)
## Parameters
`key` (in)
: key of the element to insert
`t` (in)
: value of the element to insert
## Return value
pair of an iterator to the (possibly newly inserted) element, and a `bool` that is `true` if insertion
took place and `false` if an element with an equal key already existed
## Complexity
Linear in the number of elements.
## Examples
??? example
The example shows how `emplace` is used.
```cpp
--8<-- "examples/ordered_map__emplace.cpp"
```
Output:
```
--8<-- "examples/ordered_map__emplace.output"
```
## Version history
- Added in version 3.9.0 to implement [`nlohmann::ordered_json`](../ordered_json.md).
- Overload (2) added in version 3.11.0.
+75
View File
@@ -0,0 +1,75 @@
# <small>nlohmann::ordered_map::</small>erase
```cpp
// (1)
size_type erase(const key_type& key);
// (2)
template<class KeyType>
size_type erase(KeyType&& key);
// (3)
iterator erase(iterator pos);
// (4)
iterator erase(iterator first, iterator last);
```
1. Removes the element with key equal to `key`, if any, preserving the relative order of the remaining
elements.
2. Same as (1), but for any `KeyType` comparable to `key_type` via [`key_compare`](key_compare.md)
(heterogeneous lookup). Only participates in overload resolution if `KeyType` is usable as a key type.
3. Removes the element at `pos`.
4. Removes the elements in range `[first, last)`.
## Template parameters
`KeyType`
: a type comparable to `key_type` via [`key_compare`](key_compare.md)
## Parameters
`key` (in)
: key of the element to remove
`pos` (in)
: iterator to the element to remove
`first` (in)
: iterator to the first element to remove
`last` (in)
: iterator one past the last element to remove
## Return value
1. number of elements removed (0 or 1)
2. number of elements removed (0 or 1)
3. iterator following the removed element
4. iterator following the last removed element
## Complexity
Linear in the number of elements (elements after the removed one(s) are shifted to keep storage
contiguous).
## Examples
??? example
The example shows how `erase` is used.
```cpp
--8<-- "examples/ordered_map__erase.cpp"
```
Output:
```
--8<-- "examples/ordered_map__erase.output"
```
## Version history
- Added in version 3.9.0 to implement [`nlohmann::ordered_json`](../ordered_json.md).
- Overload (2) added in version 3.11.0.
+56
View File
@@ -0,0 +1,56 @@
# <small>nlohmann::ordered_map::</small>find
```cpp
// (1)
iterator find(const key_type& key);
const_iterator find(const key_type& key) const;
// (2)
template<class KeyType>
iterator find(KeyType&& key);
template<class KeyType>
const_iterator find(KeyType&& key) const;
```
1. Returns an iterator to the element with key equal to `key`, or `end()` if no such element exists.
2. Same as (1), but for any `KeyType` comparable to `key_type` via [`key_compare`](key_compare.md)
(heterogeneous lookup). Only participates in overload resolution if `KeyType` is usable as a key type.
## Template parameters
`KeyType`
: a type comparable to `key_type` via [`key_compare`](key_compare.md)
## Parameters
`key` (in)
: key of the element to find
## Return value
iterator to the element with key equal to `key`, or `end()` if not found
## Complexity
Linear in the number of elements.
## Examples
??? example
The example shows how `find` is used.
```cpp
--8<-- "examples/ordered_map__find.cpp"
```
Output:
```
--8<-- "examples/ordered_map__find.output"
```
## Version history
- Added in version 3.9.1 to implement [`nlohmann::ordered_json`](../ordered_json.md).
- Overload (2) added in version 3.11.0.
@@ -6,7 +6,7 @@ template<class Key, class T, class IgnoredLess = std::less<Key>,
struct ordered_map : std::vector<std::pair<const Key, T>, Allocator>;
```
A minimal map-like container that preserves insertion order for use within [`nlohmann::ordered_json`](ordered_json.md)
A minimal map-like container that preserves insertion order for use within [`nlohmann::ordered_json`](../ordered_json.md)
(`nlohmann::basic_json<ordered_map>`).
## Template parameters
@@ -30,19 +30,19 @@ case all iterators (including the `end()` iterator) and all references to the el
When the storage grows, the keys are copied and the mapped values are moved to the new storage. A plain `std::vector`
would copy the whole elements instead, because their `#!cpp const` keys make them not nothrow move constructible; for
[`ordered_json`](ordered_json.md), this would be a deep copy of every nested value. The values are only copied if
[`ordered_json`](../ordered_json.md), this would be a deep copy of every nested value. The values are only copied if
`T` is not default constructible or not nothrow move assignable.
## Member types
- **key_type** - key type (`Key`)
- **mapped_type** - mapped type (`T`)
- **Container** - base container type (`#!cpp std::vector<std::pair<const Key, T>, Allocator>`)
- [**Container**](Container.md) - base container type (`#!cpp std::vector<std::pair<const Key, T>, Allocator>`)
- **iterator**
- **const_iterator**
- **size_type**
- **value_type**
- **key_compare** - key comparison function
- [**key_compare**](key_compare.md) - key comparison function
```cpp
std::equal_to<Key> // until C++14
@@ -51,15 +51,16 @@ std::equal_to<> // since C++14
## Member functions
- (constructor)
- (destructor)
- **emplace**
- **operator\[\]**
- **at**
- **erase**
- **count**
- **find**
- **insert**
- [(constructor)](ordered_map.md)
- [(destructor)](~ordered_map.md)
- [**operator=**](operator=.md)
- [**emplace**](emplace.md)
- [**operator\[\]**](operator[].md)
- [**at**](at.md)
- [**erase**](erase.md)
- [**count**](count.md)
- [**find**](find.md)
- [**insert**](insert.md)
## Exception safety
@@ -89,7 +90,7 @@ This differs from `#!cpp std::map`, where the same operations are O(log n).
!!! warning "Quadratic cost of building large objects"
Because every insertion scans all elements inserted so far, building an object of `n` distinct keys costs
**O(n²)** in total. This applies to filling an [`ordered_json`](ordered_json.md) object key by key as well as to
**O(n²)** in total. This applies to filling an [`ordered_json`](../ordered_json.md) object key by key as well as to
parsing one, since the parser inserts each key as it is read.
The cost is negligible for the object sizes typically found in configuration files or API payloads, but it grows
@@ -106,7 +107,7 @@ This differs from `#!cpp std::map`, where the same operations are O(log n).
If key order matters for objects of that size, consider a container with a lookup index, such as
[`tsl::ordered_map`](https://github.com/Tessil/ordered-map)
([integration](https://github.com/nlohmann/json/issues/546#issuecomment-304447518)), as the object type -- see
[object order](../features/object_order.md).
[object order](../../features/object_order.md).
## Examples
@@ -126,10 +127,10 @@ This differs from `#!cpp std::map`, where the same operations are O(log n).
## See also
- [ordered_json](ordered_json.md)
- [ordered_json](../ordered_json.md)
## Version history
- Added in version 3.9.0 to implement [`nlohmann::ordered_json`](ordered_json.md).
- Added in version 3.9.0 to implement [`nlohmann::ordered_json`](../ordered_json.md).
- Added **key_compare** member in version 3.11.0.
- Changed in version 3.13.0: growing the storage moves the mapped values instead of copying them.
@@ -0,0 +1,63 @@
# <small>nlohmann::ordered_map::</small>insert
```cpp
// (1)
std::pair<iterator, bool> insert(value_type&& value);
std::pair<iterator, bool> insert(const value_type& value);
// (2)
template<typename InputIt>
void insert(InputIt first, InputIt last);
```
1. Inserts `value` if no element with an equal key already exists (per [`key_compare`](key_compare.md)),
appending it at the end to preserve insertion order. If an equal key already exists, does nothing.
2. Inserts the elements from range `[first, last)`, in iteration order, applying the same equal-key rule
as (1) to each element.
## Template parameters
`InputIt`
: an input iterator type
## Parameters
`value` (in)
: value to insert
`first` (in)
: iterator to the first element to insert
`last` (in)
: iterator one past the last element to insert
## Return value
1. pair of an iterator to the (possibly newly inserted) element, and a `bool` that is `true` if insertion
took place and `false` if an element with an equal key already existed
2. (none)
## Complexity
1. Linear in the number of elements.
2. Linear in the distance between `first` and `last`, times linear in the number of elements.
## Examples
??? example
The example shows how `insert` is used.
```cpp
--8<-- "examples/ordered_map__insert.cpp"
```
Output:
```
--8<-- "examples/ordered_map__insert.output"
```
## Version history
- Added in version 3.9.1 to implement [`nlohmann::ordered_json`](../ordered_json.md).
@@ -0,0 +1,34 @@
# <small>nlohmann::ordered_map::</small>key_compare
```cpp
using key_compare = std::equal_to<Key>; // until C++14
using key_compare = std::equal_to<>; // since C++14
```
The comparator used to determine key equality when looking up elements. Unlike `std::map`, `ordered_map`
uses linear search with `key_compare` rather than an ordering relation, since element order reflects
insertion order rather than key order.
Since C++14, the transparent `#!cpp std::equal_to<>` is used, which enables heterogeneous lookup (e.g.
looking up by a `#!cpp const char*` key without constructing a temporary `Key`).
## Examples
??? example
The example shows how `key_compare` is used.
```cpp
--8<-- "examples/ordered_map__key_compare.cpp"
```
Output:
```
--8<-- "examples/ordered_map__key_compare.output"
```
## Version history
- Added in version 3.11.0.
@@ -0,0 +1,32 @@
# <small>nlohmann::ordered_map::</small>operator=
```cpp
// (1)
ordered_map& operator=(const ordered_map& other);
// (2)
ordered_map& operator=(ordered_map&& other) noexcept(std::is_nothrow_move_assignable<Container>::value);
```
1. Copy assignment operator.
2. Move assignment operator.
## Parameters
`other` (in)
: value to assign from
## Return value
`*this`
## Complexity
1. Linear in the size of `other`.
2. Constant.
<!-- NOLINT Examples -->
## Version history
- Added in version 3.9.0 to implement [`nlohmann::ordered_json`](../ordered_json.md).
@@ -0,0 +1,62 @@
# <small>nlohmann::ordered_map::</small>operator[]
```cpp
// (1)
T& operator[](const key_type& key);
const T& operator[](const key_type& key) const;
// (2)
template<class KeyType>
T& operator[](KeyType&& key);
template<class KeyType>
const T& operator[](KeyType&& key) const;
```
1. Returns a reference to the value mapped to `key`, inserting a default-constructed `T` (non-`const`
overload only) if no such element exists yet.
2. Same as (1), but for any `KeyType` comparable to `key_type` via [`key_compare`](key_compare.md)
(heterogeneous lookup). Only participates in overload resolution if `KeyType` is usable as a key type.
## Template parameters
`KeyType`
: a type comparable to `key_type` via [`key_compare`](key_compare.md)
## Parameters
`key` (in)
: key of the element to find or insert
## Return value
reference to the mapped value of the element with key equal to `key`
## Exceptions
The `const` overloads throw `std::out_of_range` if no element with key `key` exists (they delegate to
[`at`](at.md)).
## Complexity
Linear in the number of elements.
## Examples
??? example
The example shows how `operator[]` is used.
```cpp
--8<-- "examples/ordered_map__operator_idx.cpp"
```
Output:
```
--8<-- "examples/ordered_map__operator_idx.output"
```
## Version history
- Added in version 3.9.0 to implement [`nlohmann::ordered_json`](../ordered_json.md).
- Overload (2) added in version 3.11.0.
@@ -0,0 +1,66 @@
# <small>nlohmann::ordered_map::</small>ordered_map
```cpp
// (1)
ordered_map() noexcept(noexcept(Container()));
// (2)
explicit ordered_map(const Allocator& alloc) noexcept(noexcept(Container(alloc)));
// (3)
template <class It>
ordered_map(It first, It last, const Allocator& alloc = Allocator());
// (4)
ordered_map(std::initializer_list<value_type> init, const Allocator& alloc = Allocator());
// (5)
ordered_map(const ordered_map&) = default;
// (6)
ordered_map(ordered_map&&) noexcept(std::is_nothrow_move_constructible<Container>::value) = default;
```
1. Default constructor. Creates an empty `ordered_map`.
2. Creates an empty `ordered_map` using the given allocator.
3. Creates an `ordered_map` from the elements in range `[first, last)`, inserted in iteration order.
4. Creates an `ordered_map` from an initializer list of key/value pairs, inserted in list order.
5. Copy constructor.
6. Move constructor.
These constructors are declared explicitly (rather than inherited via `#!cpp using Container::Container`)
because older compilers (GCC <= 5.5, Xcode <= 9.4) do not handle the inherited constructors correctly.
## Template parameters
`It`
: an input iterator type
## Parameters
`alloc` (in)
: allocator to use for the underlying container
`first` (in)
: iterator to the first element to insert
`last` (in)
: iterator one past the last element to insert
`init` (in)
: initializer list of key/value pairs to insert
## Complexity
1. Constant.
2. Constant.
3. Linear in the distance between `first` and `last`.
4. Linear in the size of `init`.
5. Linear in the size of `other`.
6. Constant.
<!-- NOLINT Examples -->
## Version history
- Added in version 3.9.0 to implement [`nlohmann::ordered_json`](../ordered_json.md).
@@ -0,0 +1,17 @@
# <small>nlohmann::ordered_map::</small>~ordered_map
```cpp
~ordered_map() = default;
```
Destroys the `ordered_map` and frees all allocated memory.
## Complexity
Linear in the number of elements.
<!-- NOLINT Examples -->
## Version history
- Added in version 3.9.0 to implement [`nlohmann::ordered_json`](../ordered_json.md).
@@ -1,19 +0,0 @@
#include <iostream>
#include <nlohmann/json.hpp>
#include <nlohmann/json_view.hpp>
using json_document = nlohmann::json_document;
int main()
{
std::cout << std::boolalpha;
// accept() behaves exactly like basic_json::accept(): the same inputs are
// accepted or rejected, with the same ignore_comments/ignore_trailing_commas
// options
std::cout << json_document::accept(R"({"a": 1})") << '\n';
std::cout << json_document::accept(R"({"a": 1,})") << '\n'; // trailing comma: rejected by default
std::cout << json_document::accept(R"({"a": 1,})", false, true) << '\n'; // ignore_trailing_commas
std::cout << (json_document::accept(R"({"a": 1})") == nlohmann::json::accept(R"({"a": 1})")) << '\n';
}
@@ -1,4 +0,0 @@
true
false
true
true
@@ -1,23 +0,0 @@
#include <iostream>
#include <utility>
#include <nlohmann/json_view.hpp>
using json_document = nlohmann::json_document;
int main()
{
std::cout << std::boolalpha;
// the default constructor creates an empty (discarded) document
json_document empty;
std::cout << empty.is_discarded() << '\n';
// json_document is move-only: parse() itself returns by value (moved out),
// and a document can be moved again, e.g. into a container
json_document doc = json_document::parse(R"({"a": 1})");
json_document moved = std::move(doc);
std::cout << moved.root().is_object() << '\n';
// copying is disabled at compile time:
// json_document another = moved; // does not compile
}

Some files were not shown because too many files have changed in this diff Show More