Merge branch 'develop' into claude/binary-reader-narrow-numbers

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

.github/workflows/publish_documentation.yml

@@ -7,16 +7,6 @@ on:
       - develop
     paths:
       - docs/mkdocs/**
-      # the site also embeds these files via pymdownx.snippets
-      # (mkdocs.yml sets restrict_base_path: false for this)
-      - .clang-tidy
-      - .github/CODE_OF_CONDUCT.md
-      - .github/CONTRIBUTING.md
-      - .github/SECURITY.md
-      - cmake/clang_flags.cmake
-      - cmake/gcc_flags.cmake
-      - tests/fmt_formatter/project/main.cpp
-      - tools/astyle/.astylerc
   workflow_dispatch:
 
 # we don't want to have concurrent jobs, and we don't want to cancel running jobs to avoid broken publications
@@ -33,7 +23,7 @@ jobs:
       contents: write
 
     if: github.repository == 'nlohmann/json'
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     steps:
       - name: Harden Runner
         uses: step-security/harden-runner@e14015d583714f6e62063499dc959a02595150a1 # v2.21.1

.github/workflows/ubuntu.yml

@@ -346,8 +346,6 @@ jobs:
     container: intel/oneapi-hpckit:latest
     steps:
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
-        with:
-          persist-credentials: false
       - name: Get latest CMake and ninja
         uses: lukka/get-cmake@fffaaafeea488556c2c12dad60690008bc1caacb # v4.4.2
       - name: Run CMake
@@ -360,8 +358,6 @@ jobs:
     container: nvcr.io/nvidia/nvhpc:25.5-devel-cuda12.9-ubuntu22.04
     steps:
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
-        with:
-          persist-credentials: false
       - name: Get latest CMake and ninja
         uses: lukka/get-cmake@fffaaafeea488556c2c12dad60690008bc1caacb # v4.4.2
       - name: Run CMake

.github/workflows/windows.yml

@@ -87,8 +87,6 @@ jobs:
 
     steps:
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
-        with:
-          persist-credentials: false
       - name: Get latest CMake and ninja
         uses: lukka/get-cmake@fffaaafeea488556c2c12dad60690008bc1caacb # v4.4.2
       - name: Set extra CXX_FLAGS for latest std_version
@@ -125,8 +123,6 @@ jobs:
 
     steps:
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
-        with:
-          persist-credentials: false
       - name: Run CMake (Release)
         run: cmake -S . -B build -G "Visual Studio 18 2026" -A ARM64 -DJSON_BuildTests=On -DCMAKE_CXX_FLAGS="/W4 /WX"
         if: matrix.build_type == 'Release'

docs/Makefile

@@ -11,31 +11,20 @@ EXAMPLES = $(wildcard mkdocs/docs/examples/*.cpp)
 
 cxx_standard = $(lastword c++11 $(filter c++%, $(subst ., ,$1)))
 
-# common compile flags for the stand-alone example files
-EXAMPLE_CPPFLAGS = -I $(SRCDIR) -DJSON_USE_GLOBAL_UDLS=0
-EXAMPLE_WARNFLAGS = -Werror=deprecated-declarations
-
-# examples that document deprecated API and are allowed to use it
-DEPRECATED_EXAMPLES = $(addprefix mkdocs/docs/examples/, \
-	json_pointer__operator__equal_stringtype \
-	json_pointer__operator__notequal_stringtype \
-	json_pointer__operator_string_t)
-$(DEPRECATED_EXAMPLES:=.output) $(DEPRECATED_EXAMPLES:=.test): EXAMPLE_WARNFLAGS = -Wno-deprecated-declarations
-
 # create output from a stand-alone example file
 %.output: %.cpp
-	@echo "standard $(call cxx_standard,$(<:.cpp=))"
+	@echo "standard $(call cxx_standard $(<:.cpp=))"
 	$(MAKE) $(<:.cpp=) \
-		CPPFLAGS="$(EXAMPLE_CPPFLAGS)" \
-		CXXFLAGS="-std=$(call cxx_standard,$(<:.cpp=)) $(EXAMPLE_WARNFLAGS)"
+		CPPFLAGS="-I $(SRCDIR) -DJSON_USE_GLOBAL_UDLS=0" \
+		CXXFLAGS="-std=$(call cxx_standard,$(<:.cpp=)) -Wno-deprecated-declarations"
 	./$(<:.cpp=) > $@
 	rm $(<:.cpp=)
 
 # compare created output with current output of the example files
 %.test: %.cpp
 	$(MAKE) $(<:.cpp=) \
-		CPPFLAGS="$(EXAMPLE_CPPFLAGS)" \
-		CXXFLAGS="-std=$(call cxx_standard,$(<:.cpp=)) $(EXAMPLE_WARNFLAGS)"
+		CPPFLAGS="-I $(SRCDIR) -DJSON_USE_GLOBAL_UDLS=0" \
+		CXXFLAGS="-std=$(call cxx_standard,$(<:.cpp=)) -Wno-deprecated-declarations"
 	./$(<:.cpp=) > $@
 	diff $@ $(<:.cpp=.output)
 	rm $(<:.cpp=) $@

docs/docset/Info.plist

@@ -13,7 +13,7 @@
     <key>dashIndexFilePath</key>
     <string>index.html</string>
     <key>DashDocSetFallbackURL</key>
-    <string>https://json.nlohmann.me/</string>
+    <string>https://nlohmann.github.io/json/</string>
     <key>isJavaScriptEnabled</key>
     <true/>
 </dict>

docs/docset/README.md

@@ -7,11 +7,10 @@ documentation browsers like [Dash](https://kapeli.com/dash), [Velocity](https://
 The docset can be created with
 
 ```sh
-make JSON_for_Modern_C++.docset
+make nlohmann_json.docset
 ```
 
-The generated folder `JSON_for_Modern_C++.docset` can then be opened in the documentation browser. `make all` builds a
-`JSON_for_Modern_C++.tgz` archive instead, and `make install_docset_zeal` installs the docset for Zeal directly.
+The generated folder `nlohmann_json.docset` can then be opened in the documentation browser.
 
 A recent version is also part of the [Dash user contributions](https://github.com/Kapeli/Dash-User-Contributions/tree/master/docsets/JSON_for_Modern_C%2B%2B).
 

docs/mkdocs/docs/api/basic_json/number_float_t.md

@@ -55,6 +55,10 @@ This implementation does exactly follow this approach, as it uses double precisi
 smaller than `-1.79769313486232e+308` and values greater than `1.79769313486232e+308` will be stored as NaN internally
 and be serialized to `null`.
 
+During deserialization (from JSON text or any of the binary formats), a finite number that does not fit into
+`number_float_t` is rejected with [`out_of_range.406`](../../home/exceptions.md#jsonexceptionout_of_range406), for
+example a double-precision number in a binary format when `number_float_t` is `#!cpp float`.
+
 #### Storage
 
 Floating-point number values are stored directly inside a `basic_json` type.

docs/mkdocs/docs/api/basic_json/number_integer_t.md

@@ -47,11 +47,12 @@ With the default values for `NumberIntegerType` (`std::int64_t`), the default va
 
 When the default type is used, the maximal integer number that can be stored is `9223372036854775807` (INT64_MAX) and
 the minimal integer number that can be stored is `-9223372036854775808` (INT64_MIN). Integer numbers that are out of
-range will yield over/underflow when used in a constructor. During deserialization, too large or small integer numbers
-will automatically be stored as [`number_unsigned_t`](number_unsigned_t.md) or [`number_float_t`](number_float_t.md).
+range will yield over/underflow when used in a constructor. During deserialization (from JSON text or any of the binary
+formats), too large or small integer numbers will automatically be stored as [`number_unsigned_t`](number_unsigned_t.md)
+or [`number_float_t`](number_float_t.md).
 
 [RFC 8259](https://tools.ietf.org/html/rfc8259) further states:
-> Note that when such software is used, numbers that are integers and are in the range [-2<sup>53</sup>+1, 2<sup>53</sup>-1] are
+> Note that when such software is used, numbers that are integers and are in the range $[-2^{53}+1, 2^{53}-1]$ are
 > interoperable in the sense that implementations will agree exactly on their numeric values.
 
 As this range is a subrange of the exactly supported range [INT64_MIN, INT64_MAX], this class's integer type is

docs/mkdocs/docs/api/basic_json/number_unsigned_t.md

@@ -48,11 +48,12 @@ With the default values for `NumberUnsignedType` (`std::uint64_t`), the default
 
 When the default type is used, the maximal integer number that can be stored is `18446744073709551615` (UINT64_MAX) and
 the minimal integer number that can be stored is `0`. Integer numbers that are out of range will yield over/underflow
-when used in a constructor. During deserialization, too large or small integer numbers will automatically be stored
-as [`number_integer_t`](number_integer_t.md) or [`number_float_t`](number_float_t.md).
+when used in a constructor. During deserialization (from JSON text or any of the binary formats), too large or small
+integer numbers will automatically be stored as [`number_integer_t`](number_integer_t.md) or
+[`number_float_t`](number_float_t.md).
 
 [RFC 8259](https://tools.ietf.org/html/rfc8259) further states:
-> Note that when such software is used, numbers that are integers and are in the range [-2<sup>53</sup>+1, 2<sup>53</sup>-1] are
+> Note that when such software is used, numbers that are integers and are in the range $[-2^{53}+1, 2^{53}-1]$ are
 > interoperable in the sense that implementations will agree exactly on their numeric values.
 
 As this range is a subrange (when considered in conjunction with the `number_integer_t` type) of the exactly supported

docs/mkdocs/docs/api/basic_json/parse_error.md

@@ -54,7 +54,7 @@ classDiagram
 
 ## Notes
 
-For an input with <i>n</i> bytes, 1 is the index of the first character and <i>n</i>+1 is the index of the terminating null byte
+For an input with $n$ bytes, 1 is the index of the first character and $n+1$ is the index of the terminating null byte
 or the end of file. This also holds true when reading a byte vector for binary formats.
 
 ## Examples

docs/mkdocs/docs/examples/parse__iterator_pair.link

@@ -0,0 +1 @@
+<a target="_blank" href="https://wandbox.org/permlink/hUJYo1HWmfTBLMGn"><b>online</b></a>

docs/mkdocs/docs/examples/parse__pointers.link

@@ -0,0 +1 @@
+<a target="_blank" href="https://wandbox.org/permlink/AWbpa8e1xRV3y4MM"><b>online</b></a>

docs/mkdocs/docs/features/binary_formats/bjdata.md

@@ -61,7 +61,7 @@ The library uses the following mapping from JSON values types to BJData types ac
 
     The following values can **not** be converted to a BJData value:
 
-      - strings with more than 18446744073709551615 bytes, i.e., 2<sup>64</sup>-1 bytes (theoretical)
+      - strings with more than 18446744073709551615 bytes, i.e., $2^{64}-1$ bytes (theoretical)
 
 !!! info "Unused BJData markers"
 

docs/mkdocs/docs/features/binary_formats/cbor.md

@@ -168,9 +168,9 @@ The library maps CBOR types to JSON value types as follows:
 !!! warning "Negative integer overflow"
 
     CBOR negative integers (major type 1) are decoded as `-1 - n`. If the encoded magnitude `n` is too large for the
-    result to fit into `number_integer_t` (`std::int64_t` by default), parsing fails with a
-    [`parse_error.112`](../../home/exceptions.md#jsonexceptionparse_error112) exception rather than overflowing
-    silently.
+    result to fit into `number_integer_t` (`std::int64_t` by default), the result is stored as `number_float_t`, like
+    a too small integer in JSON text. For example, `-18446744073709551616` (`0x3B` followed by eight `0xFF` bytes) is
+    stored as `-1.8446744073709552e+19`.
 
 !!! warning "Object keys"
 

docs/mkdocs/docs/features/types/index.md

@@ -273,7 +273,7 @@ When the default type is used, the maximal unsigned integer number that can be s
 
 [RFC 8259](https://tools.ietf.org/html/rfc8259) further states:
 
-> Note that when such software is used, numbers that are integers and are in the range [-2<sup>53</sup>+1, 2<sup>53</sup>-1] are interoperable in the sense that implementations will agree exactly on their numeric values.
+> Note that when such software is used, numbers that are integers and are in the range $[-2^{53}+1, 2^{53}-1]$ are interoperable in the sense that implementations will agree exactly on their numeric values.
 
 As this range is a subrange of the exactly supported range [`INT64_MIN`, `INT64_MAX`], this class's integer type is interoperable.
 

docs/mkdocs/docs/features/types/number_handling.md

@@ -48,7 +48,7 @@ On number interoperability, the following remarks are made:
     for numeric magnitude and precision than is widely available.
     
     Note that when such software is used, numbers that are integers and
-    are in the range [-2<sup>53</sup>+1, 2<sup>53</sup>-1] are interoperable in the
+    are in the range $[-2^{53}+1, 2^{53}-1]$ are interoperable in the
     sense that implementations will agree exactly on their numeric
     values.
 
@@ -95,9 +95,9 @@ This is the same behavior as the code `#!c double x = 3.141592653589793238462643
 
 !!! success "Interoperability"
 
-    - The library is interoperable with respect to the specification, because its supported range [-2<sup>63</sup>, 2<sup>64</sup>-1] is
-      larger than the described range [-2<sup>53</sup>+1, 2<sup>53</sup>-1].
-    - All integers outside the range [-2<sup>63</sup>, 2<sup>64</sup>-1], as well as floating-point numbers are stored as `double`.
+    - The library is interoperable with respect to the specification, because its supported range $[-2^{63}, 2^{64}-1]$ is
+      larger than the described range $[-2^{53}+1, 2^{53}-1]$.
+    - All integers outside the range $[-2^{63}, 2^{64}-1]$, as well as floating-point numbers are stored as `double`.
       This also concurs with the specification above.
 
 ### Zeros

docs/mkdocs/docs/home/exceptions.md

@@ -331,9 +331,6 @@ An unexpected byte was read in a [binary format](../features/binary_formats/inde
     [json.exception.parse_error.112] parse error at byte 15: syntax error while parsing BSON binary: byte array length cannot be negative, is -1
     ```
     ```
-    [json.exception.parse_error.112] parse error at byte 9: syntax error while parsing CBOR value: negative integer overflow
-    ```
-    ```
     [json.exception.parse_error.112] parse error at byte 5: syntax error while parsing BSON document: document size 6 does not match the number of bytes read (5)
     ```
 
@@ -854,13 +851,18 @@ The JSON Patch operations 'remove' and 'add' cannot be applied to the root eleme
 
 ### json.exception.out_of_range.406
 
-A parsed number could not be stored as without changing it to NaN or INF.
+A parsed number could not be stored without changing it to NaN or INF. For the binary formats, this happens when a
+finite floating-point number does not fit into [`number_float_t`](../api/basic_json/number_float_t.md), for example a
+double-precision number when `number_float_t` is `#!cpp float`.
 
-!!! failure "Example message"
+!!! failure "Example messages"
 
     ```
     number overflow parsing '10E1000'
     ```
+    ```
+    [json.exception.out_of_range.406] syntax error while parsing CBOR value: number overflow
+    ```
 
 ### json.exception.out_of_range.407
 

docs/mkdocs/mkdocs.yml

@@ -349,6 +349,7 @@ markdown_extensions:
   - toc:
       permalink: true
   - md_in_html
+  - pymdownx.arithmatex
   - pymdownx.betterem:
       smart_enable: all
   - pymdownx.caret
@@ -440,3 +441,6 @@ plugins:
 
 extra_css:
   - css/custom.css
+
+extra_javascript:
+  - https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.0/MathJax.js?config=TeX-MML-AM_CHTML

docs/mkdocs/scripts/check_structure.py

@@ -79,9 +79,9 @@ def check_structure() -> None:
                     report("whitespace/line_length", f"{file}:{lineno+1} ({current_section})", f"line is too long ({len(line)} vs. 160 chars)")
 
                 # sections in `<!-- NOLINT -->` comments are treated as present
-                nolint_match = re.match(r"<!--\s*NOLINT\s+(.*?)\s*-->", line)
-                if nolint_match:
-                    current_section = nolint_match.group(1)
+                if line.startswith("<!-- NOLINT"):
+                    current_section = line.strip("<!-- NOLINT")
+                    current_section = current_section.strip(" -->")
                     existing_sections.append(current_section)
 
                 # check if sections are correct
@@ -97,7 +97,7 @@ def check_structure() -> None:
                             if len(unexpected):
                                 report("style/numbering", f"{file}:{lineno} ({current_section})", f'unexpected overloads: {", ".join([f"({x})" for x in unexpected])}')
 
-                    current_section = line[3:]
+                    current_section = line.strip("## ")
                     existing_sections.append(current_section)
 
                     if current_section in expected_sections:
@@ -141,7 +141,7 @@ def check_structure() -> None:
                 # check that non-example admonitions have titles
                 untitled_admonition = re.match(r"^(\?\?\?|!!!) ([^ ]+)$", line)
                 if untitled_admonition and untitled_admonition.group(2) != "example":
-                    report("style/admonition_title", f"{file}:{lineno+1} ({current_section})", f'"{untitled_admonition.group(2)}" admonitions should have a title')
+                    report("style/admonition_title", f"{file}:{lineno} ({current_section})", f'"{untitled_admonition.group(2)}" admonitions should have a title')
 
                 previous_line = line
 

include/nlohmann/detail/input/binary_reader.hpp

@@ -559,7 +559,7 @@ class binary_reader
             case 0x01: // double
             {
                 double number{};
-                return get_number<double, true>(input_format_t::bson, number) && sax->number_float(static_cast<number_float_t>(number), "");
+                return get_number<double, true>(input_format_t::bson, number) && emit_float(input_format_t::bson, number);
             }
 
             case 0x02: // string
@@ -600,19 +600,19 @@ class binary_reader
             case 0x10: // int32
             {
                 std::int32_t value{};
-                return get_number<std::int32_t, true>(input_format_t::bson, value) && sax->number_integer(value);
+                return get_number<std::int32_t, true>(input_format_t::bson, value) && emit_signed(input_format_t::bson, value);
             }
 
             case 0x12: // int64
             {
                 std::int64_t value{};
-                return get_number<std::int64_t, true>(input_format_t::bson, value) && sax->number_integer(value);
+                return get_number<std::int64_t, true>(input_format_t::bson, value) && emit_signed(input_format_t::bson, value);
             }
 
             case 0x11: // uint64
             {
                 std::uint64_t value{};
-                return get_number<std::uint64_t, true>(input_format_t::bson, value) && sax->number_unsigned(value);
+                return get_number<std::uint64_t, true>(input_format_t::bson, value) && emit_unsigned(input_format_t::bson, value);
             }
 
             default: // anything else is not supported (yet)
@@ -638,14 +638,19 @@ class binary_reader
         {
             return false;
         }
-        const auto max_val = static_cast<NumberType>((std::numeric_limits<number_integer_t>::max)());
-        if (number > max_val)
+
+        // the value is -1 - number, which fits into number_integer_t
+        // whenever number does
+        if (JSON_HEDLEY_LIKELY(value_in_range_of<number_integer_t>(number)))
         {
-            return sax->parse_error(chars_read, get_token_string(),
-                                    parse_error::create(112, chars_read,
-                                            exception_message(input_format_t::cbor, "negative integer overflow", "value"), nullptr));
+            return sax->number_integer(static_cast<number_integer_t>(-1) - static_cast<number_integer_t>(number));
         }
-        return sax->number_integer(static_cast<number_integer_t>(-1) - static_cast<number_integer_t>(number));
+
+        // like the lexer does for JSON text, store a value too small for
+        // number_integer_t as number_float_t; compute it as long double so
+        // that emit_float sees a finite value and can detect an overflow of
+        // number_float_t
+        return emit_float(input_format_t::cbor, static_cast<long double>(-1) - static_cast<long double>(number));
     }
 
     /*!
@@ -702,25 +707,25 @@ class binary_reader
             case 0x18: // Unsigned integer (one-byte uint8_t follows)
             {
                 std::uint8_t number{};
-                return get_number(input_format_t::cbor, number) && sax->number_unsigned(number);
+                return get_number(input_format_t::cbor, number) && emit_unsigned(input_format_t::cbor, number);
             }
 
             case 0x19: // Unsigned integer (two-byte uint16_t follows)
             {
                 std::uint16_t number{};
-                return get_number(input_format_t::cbor, number) && sax->number_unsigned(number);
+                return get_number(input_format_t::cbor, number) && emit_unsigned(input_format_t::cbor, number);
             }
 
             case 0x1A: // Unsigned integer (four-byte uint32_t follows)
             {
                 std::uint32_t number{};
-                return get_number(input_format_t::cbor, number) && sax->number_unsigned(number);
+                return get_number(input_format_t::cbor, number) && emit_unsigned(input_format_t::cbor, number);
             }
 
             case 0x1B: // Unsigned integer (eight-byte uint64_t follows)
             {
                 std::uint64_t number{};
-                return get_number(input_format_t::cbor, number) && sax->number_unsigned(number);
+                return get_number(input_format_t::cbor, number) && emit_unsigned(input_format_t::cbor, number);
             }
 
             // Negative integer -1-0x00..-1-0x17 (-1..-24)
@@ -1165,13 +1170,13 @@ class binary_reader
             case 0xFA: // Single-Precision Float (four-byte IEEE 754)
             {
                 float number{};
-                return get_number(input_format_t::cbor, number) && sax->number_float(static_cast<number_float_t>(number), "");
+                return get_number(input_format_t::cbor, number) && emit_float(input_format_t::cbor, number);
             }
 
             case 0xFB: // Double-Precision Float (eight-byte IEEE 754)
             {
                 double number{};
-                return get_number(input_format_t::cbor, number) && sax->number_float(static_cast<number_float_t>(number), "");
+                return get_number(input_format_t::cbor, number) && emit_float(input_format_t::cbor, number);
             }
 
             default: // anything else (0xFF is handled inside the other types)
@@ -1935,61 +1940,61 @@ class binary_reader
             case 0xCA: // float 32
             {
                 float number{};
-                return get_number(input_format_t::msgpack, number) && sax->number_float(static_cast<number_float_t>(number), "");
+                return get_number(input_format_t::msgpack, number) && emit_float(input_format_t::msgpack, number);
             }
 
             case 0xCB: // float 64
             {
                 double number{};
-                return get_number(input_format_t::msgpack, number) && sax->number_float(static_cast<number_float_t>(number), "");
+                return get_number(input_format_t::msgpack, number) && emit_float(input_format_t::msgpack, number);
             }
 
             case 0xCC: // uint 8
             {
                 std::uint8_t number{};
-                return get_number(input_format_t::msgpack, number) && sax->number_unsigned(number);
+                return get_number(input_format_t::msgpack, number) && emit_unsigned(input_format_t::msgpack, number);
             }
 
             case 0xCD: // uint 16
             {
                 std::uint16_t number{};
-                return get_number(input_format_t::msgpack, number) && sax->number_unsigned(number);
+                return get_number(input_format_t::msgpack, number) && emit_unsigned(input_format_t::msgpack, number);
             }
 
             case 0xCE: // uint 32
             {
                 std::uint32_t number{};
-                return get_number(input_format_t::msgpack, number) && sax->number_unsigned(number);
+                return get_number(input_format_t::msgpack, number) && emit_unsigned(input_format_t::msgpack, number);
             }
 
             case 0xCF: // uint 64
             {
                 std::uint64_t number{};
-                return get_number(input_format_t::msgpack, number) && sax->number_unsigned(number);
+                return get_number(input_format_t::msgpack, number) && emit_unsigned(input_format_t::msgpack, number);
             }
 
             case 0xD0: // int 8
             {
                 std::int8_t number{};
-                return get_number(input_format_t::msgpack, number) && sax->number_integer(number);
+                return get_number(input_format_t::msgpack, number) && emit_signed(input_format_t::msgpack, number);
             }
 
             case 0xD1: // int 16
             {
                 std::int16_t number{};
-                return get_number(input_format_t::msgpack, number) && sax->number_integer(number);
+                return get_number(input_format_t::msgpack, number) && emit_signed(input_format_t::msgpack, number);
             }
 
             case 0xD2: // int 32
             {
                 std::int32_t number{};
-                return get_number(input_format_t::msgpack, number) && sax->number_integer(number);
+                return get_number(input_format_t::msgpack, number) && emit_signed(input_format_t::msgpack, number);
             }
 
             case 0xD3: // int 64
             {
                 std::int64_t number{};
-                return get_number(input_format_t::msgpack, number) && sax->number_integer(number);
+                return get_number(input_format_t::msgpack, number) && emit_signed(input_format_t::msgpack, number);
             }
 
             case 0xDC: // array 16
@@ -2922,7 +2927,7 @@ class binary_reader
                         {
                             return sax->parse_error(chars_read, get_token_string(), out_of_range::create(408, exception_message(input_format, "excessive ndarray size caused overflow", "size"), nullptr));
                         }
-                        if (JSON_HEDLEY_UNLIKELY(!sax->number_unsigned(static_cast<number_unsigned_t>(i))))
+                        if (JSON_HEDLEY_UNLIKELY(!emit_unsigned(input_format, i)))
                         {
                             return false;
                         }
@@ -3054,37 +3059,37 @@ class binary_reader
                     break;
                 }
                 std::uint8_t number{};
-                return get_number(input_format, number) && sax->number_unsigned(number);
+                return get_number(input_format, number) && emit_unsigned(input_format, number);
             }
 
             case 'U':
             {
                 std::uint8_t number{};
-                return get_number(input_format, number) && sax->number_unsigned(number);
+                return get_number(input_format, number) && emit_unsigned(input_format, number);
             }
 
             case 'i':
             {
                 std::int8_t number{};
-                return get_number(input_format, number) && sax->number_integer(number);
+                return get_number(input_format, number) && emit_signed(input_format, number);
             }
 
             case 'I':
             {
                 std::int16_t number{};
-                return get_number(input_format, number) && sax->number_integer(number);
+                return get_number(input_format, number) && emit_signed(input_format, number);
             }
 
             case 'l':
             {
                 std::int32_t number{};
-                return get_number(input_format, number) && sax->number_integer(number);
+                return get_number(input_format, number) && emit_signed(input_format, number);
             }
 
             case 'L':
             {
                 std::int64_t number{};
-                return get_number(input_format, number) && sax->number_integer(number);
+                return get_number(input_format, number) && emit_signed(input_format, number);
             }
 
             case 'u':
@@ -3094,7 +3099,7 @@ class binary_reader
                     break;
                 }
                 std::uint16_t number{};
-                return get_number(input_format, number) && sax->number_unsigned(number);
+                return get_number(input_format, number) && emit_unsigned(input_format, number);
             }
 
             case 'm':
@@ -3104,7 +3109,7 @@ class binary_reader
                     break;
                 }
                 std::uint32_t number{};
-                return get_number(input_format, number) && sax->number_unsigned(number);
+                return get_number(input_format, number) && emit_unsigned(input_format, number);
             }
 
             case 'M':
@@ -3114,7 +3119,7 @@ class binary_reader
                     break;
                 }
                 std::uint64_t number{};
-                return get_number(input_format, number) && sax->number_unsigned(number);
+                return get_number(input_format, number) && emit_unsigned(input_format, number);
             }
 
             case 'h':
@@ -3172,13 +3177,13 @@ class binary_reader
             case 'd':
             {
                 float number{};
-                return get_number(input_format, number) && sax->number_float(static_cast<number_float_t>(number), "");
+                return get_number(input_format, number) && emit_float(input_format, number);
             }
 
             case 'D':
             {
                 double number{};
-                return get_number(input_format, number) && sax->number_float(static_cast<number_float_t>(number), "");
+                return get_number(input_format, number) && emit_float(input_format, number);
             }
 
             case 'H':
@@ -3645,13 +3650,13 @@ class binary_reader
             case 0x8E: // binary32
             {
                 float number{};
-                return get_number(input_format_t::bon8, number) && sax->number_float(static_cast<number_float_t>(number), "");
+                return get_number(input_format_t::bon8, number) && emit_float(input_format_t::bon8, number);
             }
 
             case 0x8F: // binary64
             {
                 double number{};
-                return get_number(input_format_t::bon8, number) && sax->number_float(static_cast<number_float_t>(number), "");
+                return get_number(input_format_t::bon8, number) && emit_float(input_format_t::bon8, number);
             }
 
             case 0xF8:
@@ -3717,7 +3722,9 @@ class binary_reader
     @brief pass an integer to the SAX parser
 
     Non-negative integers are passed as unsigned, negative integers as signed
-    numbers, like the other binary formats do.
+    numbers, like the other binary formats do. A value that does not fit the
+    number type is passed as described for @ref emit_unsigned and
+    @ref emit_signed.
 
     @param[in] number  the integer
     @return whether the SAX parser accepted the value
@@ -3726,9 +3733,9 @@ class binary_reader
     {
         if (number >= 0)
         {
-            return sax->number_unsigned(static_cast<number_unsigned_t>(number));
+            return emit_unsigned(input_format_t::bon8, static_cast<std::uint64_t>(number));
         }
-        return sax->number_integer(static_cast<number_integer_t>(number));
+        return emit_signed(input_format_t::bon8, number);
     }
 
     /*!
@@ -3785,8 +3792,7 @@ class binary_reader
             value = (value << 8) | static_cast<std::int64_t>(current);
         }
 
-        return negative ? sax->number_integer(static_cast<number_integer_t>(-(value + offset)))
-               : sax->number_unsigned(static_cast<number_unsigned_t>(value + offset));
+        return emit_bon8_integer(negative ? -(value + offset) : value + offset);
     }
 
     /*!
@@ -4083,6 +4089,88 @@ class binary_reader
         return true;
     }
 
+    /*!
+    @brief pass a signed integer read from the input to the SAX parser
+
+    Like the lexer does for JSON text, a value that does not fit into
+    number_integer_t is passed as number_unsigned_t if it is non-negative and
+    fits there, and as number_float_t otherwise. With the default number
+    types, every integer the binary formats can encode fits, so this only
+    matters for narrower custom number types.
+
+    @tparam NumberType a signed integer type
+    @param[in] format  the current format (for diagnostics)
+    @param[in] number  the integer
+    @return whether the SAX parser accepted the value
+
+    @throw out_of_range.406 if @a number overflows number_float_t (see
+           @ref emit_float)
+    */
+    template<typename NumberType>
+    bool emit_signed(const input_format_t format, const NumberType number)
+    {
+        if (JSON_HEDLEY_LIKELY(value_in_range_of<number_integer_t>(number)))
+        {
+            return sax->number_integer(static_cast<number_integer_t>(number));
+        }
+        if (value_in_range_of<number_unsigned_t>(number))
+        {
+            return sax->number_unsigned(static_cast<number_unsigned_t>(number));
+        }
+        return emit_float(format, number);
+    }
+
+    /*!
+    @brief pass an unsigned integer read from the input to the SAX parser
+
+    Like the lexer does for JSON text, a value that does not fit into
+    number_unsigned_t is passed as number_float_t.
+
+    @tparam NumberType an unsigned integer type
+    @param[in] format  the current format (for diagnostics)
+    @param[in] number  the integer
+    @return whether the SAX parser accepted the value
+
+    @throw out_of_range.406 if @a number overflows number_float_t (see
+           @ref emit_float)
+    */
+    template<typename NumberType>
+    bool emit_unsigned(const input_format_t format, const NumberType number)
+    {
+        if (JSON_HEDLEY_LIKELY(value_in_range_of<number_unsigned_t>(number)))
+        {
+            return sax->number_unsigned(static_cast<number_unsigned_t>(number));
+        }
+        return emit_float(format, number);
+    }
+
+    /*!
+    @brief pass a floating-point number read from the input to the SAX parser
+
+    Like the lexer does for JSON text, a finite value that overflows
+    number_float_t is rejected instead of silently becoming infinity. Infinity
+    and NaN in the input are passed on unchanged. Integers only overflow if
+    number_float_t cannot represent 2^64, e.g., a half-precision type.
+
+    @tparam NumberType a floating-point or integer type
+    @param[in] format  the current format (for diagnostics)
+    @param[in] number  the number
+    @return whether the SAX parser accepted the value
+
+    @throw out_of_range.406 if a finite @a number overflows number_float_t
+    */
+    template<typename NumberType>
+    bool emit_float(const input_format_t format, const NumberType number)
+    {
+        const auto result = static_cast<number_float_t>(number);
+        if (JSON_HEDLEY_UNLIKELY(std::isfinite(number) && !std::isfinite(result)))
+        {
+            return sax->parse_error(chars_read, get_token_string(),
+                                    out_of_range::create(406, exception_message(format, "number overflow", "value"), nullptr));
+        }
+        return sax->number_float(result, "");
+    }
+
     /*!
     @brief create a string by reading characters from the input
 

single_include/nlohmann/json.hpp

@@ -13326,7 +13326,7 @@ class binary_reader
             case 0x01: // double
             {
                 double number{};
-                return get_number<double, true>(input_format_t::bson, number) && sax->number_float(static_cast<number_float_t>(number), "");
+                return get_number<double, true>(input_format_t::bson, number) && emit_float(input_format_t::bson, number);
             }
 
             case 0x02: // string
@@ -13367,19 +13367,19 @@ class binary_reader
             case 0x10: // int32
             {
                 std::int32_t value{};
-                return get_number<std::int32_t, true>(input_format_t::bson, value) && sax->number_integer(value);
+                return get_number<std::int32_t, true>(input_format_t::bson, value) && emit_signed(input_format_t::bson, value);
             }
 
             case 0x12: // int64
             {
                 std::int64_t value{};
-                return get_number<std::int64_t, true>(input_format_t::bson, value) && sax->number_integer(value);
+                return get_number<std::int64_t, true>(input_format_t::bson, value) && emit_signed(input_format_t::bson, value);
             }
 
             case 0x11: // uint64
             {
                 std::uint64_t value{};
-                return get_number<std::uint64_t, true>(input_format_t::bson, value) && sax->number_unsigned(value);
+                return get_number<std::uint64_t, true>(input_format_t::bson, value) && emit_unsigned(input_format_t::bson, value);
             }
 
             default: // anything else is not supported (yet)
@@ -13405,14 +13405,19 @@ class binary_reader
         {
             return false;
         }
-        const auto max_val = static_cast<NumberType>((std::numeric_limits<number_integer_t>::max)());
-        if (number > max_val)
+
+        // the value is -1 - number, which fits into number_integer_t
+        // whenever number does
+        if (JSON_HEDLEY_LIKELY(value_in_range_of<number_integer_t>(number)))
         {
-            return sax->parse_error(chars_read, get_token_string(),
-                                    parse_error::create(112, chars_read,
-                                            exception_message(input_format_t::cbor, "negative integer overflow", "value"), nullptr));
+            return sax->number_integer(static_cast<number_integer_t>(-1) - static_cast<number_integer_t>(number));
         }
-        return sax->number_integer(static_cast<number_integer_t>(-1) - static_cast<number_integer_t>(number));
+
+        // like the lexer does for JSON text, store a value too small for
+        // number_integer_t as number_float_t; compute it as long double so
+        // that emit_float sees a finite value and can detect an overflow of
+        // number_float_t
+        return emit_float(input_format_t::cbor, static_cast<long double>(-1) - static_cast<long double>(number));
     }
 
     /*!
@@ -13469,25 +13474,25 @@ class binary_reader
             case 0x18: // Unsigned integer (one-byte uint8_t follows)
             {
                 std::uint8_t number{};
-                return get_number(input_format_t::cbor, number) && sax->number_unsigned(number);
+                return get_number(input_format_t::cbor, number) && emit_unsigned(input_format_t::cbor, number);
             }
 
             case 0x19: // Unsigned integer (two-byte uint16_t follows)
             {
                 std::uint16_t number{};
-                return get_number(input_format_t::cbor, number) && sax->number_unsigned(number);
+                return get_number(input_format_t::cbor, number) && emit_unsigned(input_format_t::cbor, number);
             }
 
             case 0x1A: // Unsigned integer (four-byte uint32_t follows)
             {
                 std::uint32_t number{};
-                return get_number(input_format_t::cbor, number) && sax->number_unsigned(number);
+                return get_number(input_format_t::cbor, number) && emit_unsigned(input_format_t::cbor, number);
             }
 
             case 0x1B: // Unsigned integer (eight-byte uint64_t follows)
             {
                 std::uint64_t number{};
-                return get_number(input_format_t::cbor, number) && sax->number_unsigned(number);
+                return get_number(input_format_t::cbor, number) && emit_unsigned(input_format_t::cbor, number);
             }
 
             // Negative integer -1-0x00..-1-0x17 (-1..-24)
@@ -13932,13 +13937,13 @@ class binary_reader
             case 0xFA: // Single-Precision Float (four-byte IEEE 754)
             {
                 float number{};
-                return get_number(input_format_t::cbor, number) && sax->number_float(static_cast<number_float_t>(number), "");
+                return get_number(input_format_t::cbor, number) && emit_float(input_format_t::cbor, number);
             }
 
             case 0xFB: // Double-Precision Float (eight-byte IEEE 754)
             {
                 double number{};
-                return get_number(input_format_t::cbor, number) && sax->number_float(static_cast<number_float_t>(number), "");
+                return get_number(input_format_t::cbor, number) && emit_float(input_format_t::cbor, number);
             }
 
             default: // anything else (0xFF is handled inside the other types)
@@ -14702,61 +14707,61 @@ class binary_reader
             case 0xCA: // float 32
             {
                 float number{};
-                return get_number(input_format_t::msgpack, number) && sax->number_float(static_cast<number_float_t>(number), "");
+                return get_number(input_format_t::msgpack, number) && emit_float(input_format_t::msgpack, number);
             }
 
             case 0xCB: // float 64
             {
                 double number{};
-                return get_number(input_format_t::msgpack, number) && sax->number_float(static_cast<number_float_t>(number), "");
+                return get_number(input_format_t::msgpack, number) && emit_float(input_format_t::msgpack, number);
             }
 
             case 0xCC: // uint 8
             {
                 std::uint8_t number{};
-                return get_number(input_format_t::msgpack, number) && sax->number_unsigned(number);
+                return get_number(input_format_t::msgpack, number) && emit_unsigned(input_format_t::msgpack, number);
             }
 
             case 0xCD: // uint 16
             {
                 std::uint16_t number{};
-                return get_number(input_format_t::msgpack, number) && sax->number_unsigned(number);
+                return get_number(input_format_t::msgpack, number) && emit_unsigned(input_format_t::msgpack, number);
             }
 
             case 0xCE: // uint 32
             {
                 std::uint32_t number{};
-                return get_number(input_format_t::msgpack, number) && sax->number_unsigned(number);
+                return get_number(input_format_t::msgpack, number) && emit_unsigned(input_format_t::msgpack, number);
             }
 
             case 0xCF: // uint 64
             {
                 std::uint64_t number{};
-                return get_number(input_format_t::msgpack, number) && sax->number_unsigned(number);
+                return get_number(input_format_t::msgpack, number) && emit_unsigned(input_format_t::msgpack, number);
             }
 
             case 0xD0: // int 8
             {
                 std::int8_t number{};
-                return get_number(input_format_t::msgpack, number) && sax->number_integer(number);
+                return get_number(input_format_t::msgpack, number) && emit_signed(input_format_t::msgpack, number);
             }
 
             case 0xD1: // int 16
             {
                 std::int16_t number{};
-                return get_number(input_format_t::msgpack, number) && sax->number_integer(number);
+                return get_number(input_format_t::msgpack, number) && emit_signed(input_format_t::msgpack, number);
             }
 
             case 0xD2: // int 32
             {
                 std::int32_t number{};
-                return get_number(input_format_t::msgpack, number) && sax->number_integer(number);
+                return get_number(input_format_t::msgpack, number) && emit_signed(input_format_t::msgpack, number);
             }
 
             case 0xD3: // int 64
             {
                 std::int64_t number{};
-                return get_number(input_format_t::msgpack, number) && sax->number_integer(number);
+                return get_number(input_format_t::msgpack, number) && emit_signed(input_format_t::msgpack, number);
             }
 
             case 0xDC: // array 16
@@ -15689,7 +15694,7 @@ class binary_reader
                         {
                             return sax->parse_error(chars_read, get_token_string(), out_of_range::create(408, exception_message(input_format, "excessive ndarray size caused overflow", "size"), nullptr));
                         }
-                        if (JSON_HEDLEY_UNLIKELY(!sax->number_unsigned(static_cast<number_unsigned_t>(i))))
+                        if (JSON_HEDLEY_UNLIKELY(!emit_unsigned(input_format, i)))
                         {
                             return false;
                         }
@@ -15821,37 +15826,37 @@ class binary_reader
                     break;
                 }
                 std::uint8_t number{};
-                return get_number(input_format, number) && sax->number_unsigned(number);
+                return get_number(input_format, number) && emit_unsigned(input_format, number);
             }
 
             case 'U':
             {
                 std::uint8_t number{};
-                return get_number(input_format, number) && sax->number_unsigned(number);
+                return get_number(input_format, number) && emit_unsigned(input_format, number);
             }
 
             case 'i':
             {
                 std::int8_t number{};
-                return get_number(input_format, number) && sax->number_integer(number);
+                return get_number(input_format, number) && emit_signed(input_format, number);
             }
 
             case 'I':
             {
                 std::int16_t number{};
-                return get_number(input_format, number) && sax->number_integer(number);
+                return get_number(input_format, number) && emit_signed(input_format, number);
             }
 
             case 'l':
             {
                 std::int32_t number{};
-                return get_number(input_format, number) && sax->number_integer(number);
+                return get_number(input_format, number) && emit_signed(input_format, number);
             }
 
             case 'L':
             {
                 std::int64_t number{};
-                return get_number(input_format, number) && sax->number_integer(number);
+                return get_number(input_format, number) && emit_signed(input_format, number);
             }
 
             case 'u':
@@ -15861,7 +15866,7 @@ class binary_reader
                     break;
                 }
                 std::uint16_t number{};
-                return get_number(input_format, number) && sax->number_unsigned(number);
+                return get_number(input_format, number) && emit_unsigned(input_format, number);
             }
 
             case 'm':
@@ -15871,7 +15876,7 @@ class binary_reader
                     break;
                 }
                 std::uint32_t number{};
-                return get_number(input_format, number) && sax->number_unsigned(number);
+                return get_number(input_format, number) && emit_unsigned(input_format, number);
             }
 
             case 'M':
@@ -15881,7 +15886,7 @@ class binary_reader
                     break;
                 }
                 std::uint64_t number{};
-                return get_number(input_format, number) && sax->number_unsigned(number);
+                return get_number(input_format, number) && emit_unsigned(input_format, number);
             }
 
             case 'h':
@@ -15939,13 +15944,13 @@ class binary_reader
             case 'd':
             {
                 float number{};
-                return get_number(input_format, number) && sax->number_float(static_cast<number_float_t>(number), "");
+                return get_number(input_format, number) && emit_float(input_format, number);
             }
 
             case 'D':
             {
                 double number{};
-                return get_number(input_format, number) && sax->number_float(static_cast<number_float_t>(number), "");
+                return get_number(input_format, number) && emit_float(input_format, number);
             }
 
             case 'H':
@@ -16412,13 +16417,13 @@ class binary_reader
             case 0x8E: // binary32
             {
                 float number{};
-                return get_number(input_format_t::bon8, number) && sax->number_float(static_cast<number_float_t>(number), "");
+                return get_number(input_format_t::bon8, number) && emit_float(input_format_t::bon8, number);
             }
 
             case 0x8F: // binary64
             {
                 double number{};
-                return get_number(input_format_t::bon8, number) && sax->number_float(static_cast<number_float_t>(number), "");
+                return get_number(input_format_t::bon8, number) && emit_float(input_format_t::bon8, number);
             }
 
             case 0xF8:
@@ -16484,7 +16489,9 @@ class binary_reader
     @brief pass an integer to the SAX parser
 
     Non-negative integers are passed as unsigned, negative integers as signed
-    numbers, like the other binary formats do.
+    numbers, like the other binary formats do. A value that does not fit the
+    number type is passed as described for @ref emit_unsigned and
+    @ref emit_signed.
 
     @param[in] number  the integer
     @return whether the SAX parser accepted the value
@@ -16493,9 +16500,9 @@ class binary_reader
     {
         if (number >= 0)
         {
-            return sax->number_unsigned(static_cast<number_unsigned_t>(number));
+            return emit_unsigned(input_format_t::bon8, static_cast<std::uint64_t>(number));
         }
-        return sax->number_integer(static_cast<number_integer_t>(number));
+        return emit_signed(input_format_t::bon8, number);
     }
 
     /*!
@@ -16552,8 +16559,7 @@ class binary_reader
             value = (value << 8) | static_cast<std::int64_t>(current);
         }
 
-        return negative ? sax->number_integer(static_cast<number_integer_t>(-(value + offset)))
-               : sax->number_unsigned(static_cast<number_unsigned_t>(value + offset));
+        return emit_bon8_integer(negative ? -(value + offset) : value + offset);
     }
 
     /*!
@@ -16850,6 +16856,88 @@ class binary_reader
         return true;
     }
 
+    /*!
+    @brief pass a signed integer read from the input to the SAX parser
+
+    Like the lexer does for JSON text, a value that does not fit into
+    number_integer_t is passed as number_unsigned_t if it is non-negative and
+    fits there, and as number_float_t otherwise. With the default number
+    types, every integer the binary formats can encode fits, so this only
+    matters for narrower custom number types.
+
+    @tparam NumberType a signed integer type
+    @param[in] format  the current format (for diagnostics)
+    @param[in] number  the integer
+    @return whether the SAX parser accepted the value
+
+    @throw out_of_range.406 if @a number overflows number_float_t (see
+           @ref emit_float)
+    */
+    template<typename NumberType>
+    bool emit_signed(const input_format_t format, const NumberType number)
+    {
+        if (JSON_HEDLEY_LIKELY(value_in_range_of<number_integer_t>(number)))
+        {
+            return sax->number_integer(static_cast<number_integer_t>(number));
+        }
+        if (value_in_range_of<number_unsigned_t>(number))
+        {
+            return sax->number_unsigned(static_cast<number_unsigned_t>(number));
+        }
+        return emit_float(format, number);
+    }
+
+    /*!
+    @brief pass an unsigned integer read from the input to the SAX parser
+
+    Like the lexer does for JSON text, a value that does not fit into
+    number_unsigned_t is passed as number_float_t.
+
+    @tparam NumberType an unsigned integer type
+    @param[in] format  the current format (for diagnostics)
+    @param[in] number  the integer
+    @return whether the SAX parser accepted the value
+
+    @throw out_of_range.406 if @a number overflows number_float_t (see
+           @ref emit_float)
+    */
+    template<typename NumberType>
+    bool emit_unsigned(const input_format_t format, const NumberType number)
+    {
+        if (JSON_HEDLEY_LIKELY(value_in_range_of<number_unsigned_t>(number)))
+        {
+            return sax->number_unsigned(static_cast<number_unsigned_t>(number));
+        }
+        return emit_float(format, number);
+    }
+
+    /*!
+    @brief pass a floating-point number read from the input to the SAX parser
+
+    Like the lexer does for JSON text, a finite value that overflows
+    number_float_t is rejected instead of silently becoming infinity. Infinity
+    and NaN in the input are passed on unchanged. Integers only overflow if
+    number_float_t cannot represent 2^64, e.g., a half-precision type.
+
+    @tparam NumberType a floating-point or integer type
+    @param[in] format  the current format (for diagnostics)
+    @param[in] number  the number
+    @return whether the SAX parser accepted the value
+
+    @throw out_of_range.406 if a finite @a number overflows number_float_t
+    */
+    template<typename NumberType>
+    bool emit_float(const input_format_t format, const NumberType number)
+    {
+        const auto result = static_cast<number_float_t>(number);
+        if (JSON_HEDLEY_UNLIKELY(std::isfinite(number) && !std::isfinite(result)))
+        {
+            return sax->parse_error(chars_read, get_token_string(),
+                                    out_of_range::create(406, exception_message(format, "number overflow", "value"), nullptr));
+        }
+        return sax->number_float(result, "");
+    }
+
     /*!
     @brief create a string by reading characters from the input
 

tests/src/unit-binary_formats.cpp

@@ -11,7 +11,12 @@
 #include <nlohmann/json.hpp>
 using nlohmann::json;
 
+#include <cmath>
 #include <fstream>
+#include <limits>
+#include <map>
+#include <string>
+#include <vector>
 #include "make_test_data_available.hpp"
 
 TEST_CASE("Binary Formats" * doctest::skip())
@@ -224,3 +229,139 @@ TEST_CASE("Binary Formats" * doctest::skip())
         CHECK((100.0 * double(ubjson_3_size) / double(json_size)) == Approx(89.450));
     }
 }
+
+namespace
+{
+// the binary formats as function pointers for "Binary formats with narrow number types";
+// named functions rather than lambdas, because clang 3.5 cannot convert a lambda
+// to a function pointer in the braced initializer of the format table
+using narrow_json = nlohmann::basic_json<std::map, std::vector, std::string, bool, std::int32_t, std::uint32_t, float>;
+using bytes = std::vector<std::uint8_t>;
+
+bytes encode_cbor(const json& j)
+{
+    return json::to_cbor(j);
+}
+narrow_json decode_cbor(const bytes& v, bool allow_exceptions)
+{
+    return narrow_json::from_cbor(v, true, allow_exceptions);
+}
+
+bytes encode_msgpack(const json& j)
+{
+    return json::to_msgpack(j);
+}
+narrow_json decode_msgpack(const bytes& v, bool allow_exceptions)
+{
+    return narrow_json::from_msgpack(v, true, allow_exceptions);
+}
+
+bytes encode_ubjson(const json& j)
+{
+    return json::to_ubjson(j);
+}
+narrow_json decode_ubjson(const bytes& v, bool allow_exceptions)
+{
+    return narrow_json::from_ubjson(v, true, allow_exceptions);
+}
+
+bytes encode_bjdata(const json& j)
+{
+    return json::to_bjdata(j);
+}
+narrow_json decode_bjdata(const bytes& v, bool allow_exceptions)
+{
+    return narrow_json::from_bjdata(v, true, allow_exceptions);
+}
+
+// BSON can only store numbers as object members
+bytes encode_bson(const json& j)
+{
+    return json::to_bson(json{{"a", j}});
+}
+narrow_json decode_bson(const bytes& v, bool allow_exceptions)
+{
+    const auto result = narrow_json::from_bson(v, true, allow_exceptions);
+    return result.is_discarded() ? result : result.at("a");
+}
+
+bytes encode_bon8(const json& j)
+{
+    return json::to_bon8(j);
+}
+narrow_json decode_bon8(const bytes& v, bool allow_exceptions)
+{
+    return narrow_json::from_bon8(v, true, allow_exceptions);
+}
+
+} // namespace
+
+TEST_CASE("Binary formats with narrow number types")
+{
+    // Numbers that do not fit the number types are handled like the lexer
+    // handles them in JSON text: an integer that fits neither integer type is
+    // stored as a floating-point number, and a finite floating-point number
+    // that overflows number_float_t is rejected with out_of_range.406.
+    struct binary_format
+    {
+        const char* name;
+        bytes (*encode)(const json&);
+        narrow_json (*decode)(const bytes&, bool);
+    };
+
+    const std::vector<binary_format> formats =
+    {
+        {"CBOR", encode_cbor, decode_cbor},
+        {"MessagePack", encode_msgpack, decode_msgpack},
+        {"UBJSON", encode_ubjson, decode_ubjson},
+        {"BJData", encode_bjdata, decode_bjdata},
+        {"BSON", encode_bson, decode_bson},
+        {"BON8", encode_bon8, decode_bon8},
+    };
+
+    for (const auto& format : formats)
+    {
+        const std::string name = format.name;
+        INFO("format := ", name);
+        const auto roundtrip = [&format](const json & j)
+        {
+            return format.decode(format.encode(j), true);
+        };
+
+        // integers that fit keep their type
+        CHECK(roundtrip(json(-5)).is_number_integer());
+        CHECK(roundtrip(json(-5)).get<std::int32_t>() == -5);
+        CHECK(roundtrip(json(3000000000u)).is_number_unsigned());
+        CHECK(roundtrip(json(3000000000u)).get<std::uint32_t>() == 3000000000u);
+
+        // integers that fit neither integer type are stored as float
+        CHECK(roundtrip(json(5000000000u)).is_number_float());
+        CHECK(roundtrip(json(5000000000u)).get<float>() == 5000000000.0f);
+        if (name != "BON8") // BON8 cannot encode integers above INT64_MAX
+        {
+            CHECK(roundtrip(json(10000000000000000000u)).is_number_float());
+            CHECK(roundtrip(json(10000000000000000000u)).get<float>() == 10000000000000000000.0f);
+        }
+        CHECK(roundtrip(json(-3000000000LL)).is_number_float());
+        CHECK(roundtrip(json(-3000000000LL)).get<float>() == -3000000000.0f);
+        CHECK(roundtrip(json(-5000000000LL)).is_number_float());
+        CHECK(roundtrip(json(-5000000000LL)).get<float>() == -5000000000.0f);
+
+        // floating-point numbers that fit
+        CHECK(roundtrip(json(1.5)).get<float>() == 1.5f);
+        const auto just_above_max = std::nextafter(static_cast<double>((std::numeric_limits<float>::max)()),
+                                    std::numeric_limits<double>::infinity());
+        CHECK(roundtrip(json(just_above_max)).get<float>() == (std::numeric_limits<float>::max)());
+
+        // infinity and NaN are passed on
+        CHECK(std::isinf(roundtrip(json(std::numeric_limits<double>::infinity())).get<float>()));
+        CHECK(std::isnan(roundtrip(json(std::numeric_limits<double>::quiet_NaN())).get<float>()));
+
+        // finite floating-point numbers that overflow number_float_t are rejected
+        const std::string message = "[json.exception.out_of_range.406] syntax error while parsing " + name
+                                    + " value: number overflow";
+        CHECK_THROWS_WITH_AS(roundtrip(json(1e300)), message.c_str(), narrow_json::out_of_range&);
+        CHECK_THROWS_WITH_AS(roundtrip(json(-1e300)), message.c_str(), narrow_json::out_of_range&);
+        CHECK(format.decode(format.encode(json(1e300)), false).is_discarded());
+    }
+}

tests/src/unit-cbor.cpp

@@ -3187,7 +3187,8 @@ TEST_CASE("Tagged values")
         // CBOR encodes negative integers as: result = -1 - n
         // For type 0x3B, n is an 8-byte uint64_t. Valid range for n with
         // the default int64_t is [0, INT64_MAX], producing results in [INT64_MIN, -1].
-        // When n > INT64_MAX, the result exceeds int64_t range and is rejected.
+        // When n > INT64_MAX, the result exceeds int64_t range and is stored
+        // as a floating-point number, as the lexer does for JSON text.
 
         SECTION("n = 0 is valid (result = -1)")
         {
@@ -3208,33 +3209,34 @@ TEST_CASE("Tagged values")
             CHECK(result.get<int64_t>() == (std::numeric_limits<int64_t>::min)());
         }
 
-        SECTION("n = INT64_MAX + 1 is rejected (overflow)")
+        SECTION("n = INT64_MAX + 1 is stored as float")
         {
             // n = INT64_MAX + 1 (0x8000000000000000)
-            // result = -1 - n = -9223372036854775809, which exceeds int64_t range
+            // result = -1 - n = -9223372036854775809, which exceeds int64_t range;
+            // the nearest double is -9223372036854775808.0
             const std::vector<uint8_t> input = {0x3B, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
-            json _;
-            CHECK_THROWS_WITH_AS(_ = json::from_cbor(input),
-                                 "[json.exception.parse_error.112] parse error at byte 9: syntax error while parsing CBOR value: negative integer overflow",
-                                 json::parse_error);
+            const auto result = json::from_cbor(input);
+            CHECK(result.is_number_float());
+            CHECK(result.get<double>() == -9223372036854775808.0);
+            CHECK(result == json::parse("-9223372036854775809"));
         }
 
-        SECTION("n = UINT64_MAX is rejected (overflow)")
+        SECTION("n = UINT64_MAX is stored as float")
         {
             // n = UINT64_MAX (0xFFFFFFFFFFFFFFFF)
             // result = -1 - n = -18446744073709551616, which exceeds int64_t range
             const std::vector<uint8_t> input = {0x3B, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
-            json _;
-            CHECK_THROWS_WITH_AS(_ = json::from_cbor(input),
-                                 "[json.exception.parse_error.112] parse error at byte 9: syntax error while parsing CBOR value: negative integer overflow",
-                                 json::parse_error);
+            const auto result = json::from_cbor(input);
+            CHECK(result.is_number_float());
+            CHECK(result.get<double>() == -18446744073709551616.0);
+            CHECK(result == json::parse("-18446744073709551616"));
         }
 
-        SECTION("overflow with allow_exceptions=false returns discarded")
+        SECTION("overflow with allow_exceptions=false is not an error")
         {
             const std::vector<uint8_t> input = {0x3B, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
             const auto result = json::from_cbor(input, true, false);
-            CHECK(result.is_discarded());
+            CHECK(result.is_number_float());
         }
     }