JSON for Modern C++
Release date: 2020-08-06 SHA-256: 7804b38146921d03374549c9e2a5e3acda097814c43caf2b96a0278e58df26e0 (json.hpp), 6bea5877b1541d353bd77bdfbdb2696333ae5ed8f9e8cc22df657192218cad91 (include.zip)
This release fixes two bugs in the features introduced in release 3.9.0. The lexer did not accept consecutive comments, and ordered_json lacked some functions from json. All changes are backward-compatible.
:moneybag: Note you can support this project via GitHub sponsors or PayPal.
/* one */ /* two */ []). #2330 #2332ordered_json container did not implement the complete interface of basic_json which broke existing code when json was replaced by ordered_json, in particular when trying to call ordered_json::parse. #2315 #2319 #2331CMAKE_CURRENT_BINARY_DIR instead of CMAKE_BINARY_DIR #2318CMAKE_INSTALL_LIBDIR. #2314-Wimplicit-fallthrough warning. #2333The following functions have been deprecated in earlier versions and will be removed in the next major version (i.e., 4.0.0):
iterator_wrapper are deprecated. Please use the member function items() instead.friend std::istream& operator<<(basic_json&, std::istream&) and friend std::ostream& operator>>(const basic_json&, std::ostream&) are deprecated. Please use friend std::istream& operator>>(std::istream&, basic_json&) and friend operator<<(std::ostream&, const basic_json&) instead.basic_json::parse, basic_json::accept, basic_json::sax_parse, basic_json::from_cbor, basic_json::from_msgpack, basic_json::from_ubjson, basic_json::from_bson) via initializer lists is deprecated. Instead, pass two iterators; for instance, call basic_json::from_cbor(ptr, ptr+len) instead of basic_json::from_cbor({ptr, len}).All deprecations are annotated with HEDLEY_DEPRECATED_FOR to report which function to use instead.
Release date: 2020-07-27 SHA-256: d8089d52d285ef2c5368eb39ae665b39ea464206b1ca674a88a915c0245ff4f0 (json.hpp), 5b9b819aed31626aefe2eace23498cafafc1691890556cd36d2a8002f6905009 (include.zip)
JSON for Modern C++ 3.9.0 is a feature release that adds four long-awaited features, some requested five years ago.
// and /* */ style comments. Though comments are not officially part of the JSON specification (see here for a discussion), comment support was a frequently requested feature, and its implementation was much less effort than continuously explaining the lack of comment support.nlohmann::ordered_json as drop-in replacement for nlohmann::json for this.All changes are backward-compatible. See below the complete list of changes. See the README or the documentation for more information.
:moneybag: Note you can support this project via GitHub sponsors or PayPal.
ignore_comments to the parse function will treat // and /* */ comments like whitespace. #294 #363 #376 #597 #1513 #2061 #2212nlohmann::ordered_json to preserve insertion order of object keys. ordered_json is a specialization of basic_json and can be used wherever json is used. #106 #424 #543 #660 #727 #952 #1106 #1717 #1817 #2179 #2206 #2258JSON_ImplicitConversions and preprocessor symbol JSON_USE_IMPLICIT_CONVERSIONS to switch off implicit conversions. Implicit conversions, though very practical, are also a source of subtle bugs or unexpected behavior and may be switched off by default in future versions. The new options allow to remove implicit conversions now. #958 #1559NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE and NLOHMANN_DEFINE_TYPE_INTRUSIVE to simplify serialization/deserialization code for user-defined types. #2175 #2225 #2233 #2267 #2280 #2287 #2306 #2313json.exception.out_of_range.407 will no longer occur for integers larger than 9223372036854775807 (LLONG_MAX). #2297 #2286allow_exceptions was not respected. #2299 #2298std::hash<nlohmann::basic_json> with a function that does not allocate memory. #2292 #2285 #2269FetchContent. #2222JSON_TestDataDirectory to select directory of previously downloaded test data for situations where Internet access is forbidden during testing. #2189 #2190JSON_ASSERT macro to control behavior of assert calls. #2242swap specialization to support C++20. #2176binary() function in SAX interface. #2282target_include_directories. #2279Passing iterator pairs or pointer/length pairs to parsing functions (basic_json::parse, basic_json::accept, basic_json::sax_parse, basic_json::from_cbor, basic_json::from_msgpack, basic_json::from_ubjson, basic_json::from_bson) via initializer lists is deprecated. Instead, pass two iterators; for instance, call basic_json::from_cbor(ptr, ptr+len) instead of basic_json::from_cbor({ptr, len}).
The following functions have been deprecated in earlier versions and will be removed in the next major version (i.e., 4.0.0):
iterator_wrapper are deprecated. Please use the member function items() instead.friend std::istream& operator<<(basic_json&, std::istream&) and friend std::ostream& operator>>(const basic_json&, std::ostream&) are deprecated. Please use friend std::istream& operator>>(std::istream&, basic_json&) and friend operator<<(std::ostream&, const basic_json&) instead.All deprecations are annotated with HEDLEY_DEPRECATED_FOR to report which function to use instead.
Release date: 2020-06-14 SHA-256: be7bbfbc7c62c35aa6f27dfbdd950384f247dd9f2281b5930bdaa3a6ab95eef7 (json.hpp), 8590fbcc2346a3eefc341935765dd57598022ada1081b425678f0da9a939a3c0 (include.zip)
It has been six months since the last release, and a lot of minor changes and bug fixes have accumulated. Nonetheless, JSON for Modern C++ 3.8.0 is a feature release.
With binary values we greatly extend the support for binary formats such as CBOR, BSON, or MessagePack. By adding a new value type to the JSON class, binary values can be read and written, and even shared between different formats. See the documentation for examples.
Furthermore, we overworked the input adapters; that is, the way input is read by the parsers. Now any container is supported via the LegacyInputIterator concept. See the documentation for examples. At the same time, we could improve the performance by 3-10%.
All changes are backward-compatible. See below the complete list of changes.
:moneybag: Note you can now support this project via GitHub sponsors or PayPal.
LegacyInputIterator. The encoding of the input is implicitly derived from the size of the value type: UTF-8 (1 byte), UTF-16 (2 bytes), and UTF-32 (4 bytes) are supported. #1813 #2145 #2174 #2178float as float to save space in the serialization (32 bit va. 64 bit). #1719 #2044from_bson, from_cbor, from_msgpack, and from_ubjson) now properly respect the allow_exceptions=false parameter. #1715 #2140contains function for JSON Pointers now returns false in all cases a syntactically correct JSON Pointer refers to a non-existing value. Previously, an exception was raised if a JSON Pointer referred to an array, but did not consist of a number. #1942 #1982 #2019+ as array index. #1990/- in the add operation for arrays. #1983 #2054push_back. #1971 #2025value() function with json::value_t type parameter. #2086 #2104discarded before. #1972 #2153std::is_pod usage as it is deprecated in C++20. #1913 #2033 #2109<ciso646> is deprecated in C++17 and not included if library is compiled with C++17. #2089 .#2115HEDLEY_DEPRECATED_FOR to indicate deprecated functions to have supporting compilers report which function to use instead.This release deprecates passing iterator pairs or pointer/length pairs to parsing functions (basic_json::parse, basic_json::accept, basic_json::sax_parse, basic_json::from_cbor, basic_json::from_msgpack, basic_json::from_ubjson, basic_json::from_bson) via initializer lists. Instead, pass two iterators; for instance, call basic_json::from_cbor(ptr, ptr+len) instead of basic_json::from_cbor({ptr, len}).
The following functions have been deprecated in earlier versions and will be removed in the next major version (i.e., 4.0.0):
iterator_wrapper are deprecated. Please use the member function items() instead.friend std::istream& operator<<(basic_json&, std::istream&) and friend std::ostream& operator>>(const basic_json&, std::ostream&) are deprecated. Please use friend std::istream& operator>>(std::istream&, basic_json&) and friend operator<<(std::ostream&, const basic_json&) instead.All deprecations are annotated with HEDLEY_DEPRECATED_FOR to report which function to use instead.
Release date: 2019-11-17 SHA-256: 3b5d2b8f8282b80557091514d8ab97e27f9574336c804ee666fda673a9b59926 (json.hpp), 87b5884741427220d3a33df1363ae0e8b898099fbc59f1c451113f6732891014 (include.zip)
This release fixes a bug introduced in release 3.7.2 which could yield quadratic complexity in destructor calls. All changes are backward-compatible.
reserve() calls from the destructor which could lead to quadratic complexity. #1837 #1838This release does not deprecate any functions. As an overview, the following functions have been deprecated in earlier versions and will be removed in the next major version (i.e., 4.0.0):
iterator_wrapper are deprecated. Please use the member function items() instead.friend std::istream& operator<<(basic_json&, std::istream&) and friend std::ostream& operator>>(const basic_json&, std::ostream&) are deprecated. Please use friend std::istream& operator>>(std::istream&, basic_json&) and friend operator<<(std::ostream&, const basic_json&) instead.Release date: 2019-11-10 SHA-256: 0a65fcbbe1b334d3f45c9498e5ee28c3f3b2428aea98557da4a3ff12f0f14ad6 (json.hpp), 67f69c9a93b7fa0612dc1b6273119d2c560317333581845f358aaa68bff8f087 (include.zip)
Project bad_json_parsers tested how JSON parser libraries react on deeply nested inputs. It turns out that this library segfaulted at a certain nesting depth. This bug was fixed with this release. Now the parsing is only bounded by the available memory. All changes are backward-compatible.
This release does not deprecate any functions. As an overview, the following functions have been deprecated in earlier versions and will be removed in the next major version (i.e., 4.0.0):
iterator_wrapper are deprecated. Please use the member function items() instead.friend std::istream& operator<<(basic_json&, std::istream&) and friend std::ostream& operator>>(const basic_json&, std::ostream&) are deprecated. Please use friend std::istream& operator>>(std::istream&, basic_json&) and friend operator<<(std::ostream&, const basic_json&) instead.Release date: 2019-11-06 SHA-256: b5ba7228f3c22a882d379e93d08eab4349458ee16fbf45291347994eac7dc7ce (json.hpp), 77b9f54b34e7989e6f402afb516f7ff2830df551c3a36973085e2c7a6b1045fe (include.zip)
This release fixes several small bugs in the library. All changes are backward-compatible.
std::int64_t minimum value. #1708 #1722contains() function for JSON Pointers. #1727 #1741std::pair and std::tuple to json. #1805 #1806 #1825 #1826iteration_proxy. #1797json to std::valarray.items() function can now be used with a custom string type. #1765json_pointer::back const. #1764 #1769ubuntu-latest/GCC 7.4.0 as CI step.JSON_THROW_USER, JSON_TRY_USER, and JSON_CATCH_USER macros to control user-defined exception handling.GLOB from CMake files. #1779This release does not deprecate any functions. As an overview, the following functions have been deprecated in earlier versions and will be removed in the next major version (i.e., 4.0.0):
iterator_wrapper are deprecated. Please use the member function items() instead.friend std::istream& operator<<(basic_json&, std::istream&) and friend std::ostream& operator>>(const basic_json&, std::ostream&) are deprecated. Please use friend std::istream& operator>>(std::istream&, basic_json&) and friend operator<<(std::ostream&, const basic_json&) instead.Release date: 2019-07-28 SHA-256: a503214947952b69f0062f572cb74c17582a495767446347ce2e452963fc2ca4 (json.hpp), 541c34438fd54182e9cdc68dd20c898d766713ad6d901fb2c6e28ff1f1e7c10d (include.zip)
This release introduces a few convenience functions and performs a lot of house keeping (bug fixes and small improvements). All changes are backward-compatible.
contains function to check if a JSON pointer is valid without throwing exceptions, just like its counterpart for object keys. #1600to_string to allow for generic conversion to strings. #916 #1585emplace_back function, returning a reference to the added element just like C++17 is introducing this for std::vector. #1609std::string_view in the unit tests. #1634 #1639get_to method to clear existing content before writing. #1511 #1555-Wc++17-extensions warning. nodiscard attributes are now only used with Clang when -std=c++17 is used. #1535 #1551GNUInstallDirs to set library install directories. #1673json type on the documentation start page. #1616value() function with respect to type_error.302 exception. #1601JSON_BuildTests, JSON_Install, JSON_MultipleHeaders, JSON_Sanitizer, JSON_Valgrind, JSON_NoExceptions, JSON_Coverage).JSON_DEPRECATED, JSON_NODISCARD, JSON_LIKELY, JSON_UNLIKELY, JSON_HAS_CPP_14, or JSON_HAS_CPP_17. Functions taking or returning pointers are annotated accordingly when a pointer will not be null.This release does not deprecate any functions. As an overview, the following functions have been deprecated in earlier versions and will be removed in the next major version (i.e., 4.0.0):
iterator_wrapper are deprecated. Please use the member function items() instead.friend std::istream& operator<<(basic_json&, std::istream&) and friend std::ostream& operator>>(const basic_json&, std::ostream&) are deprecated. Please use friend std::istream& operator>>(std::istream&, basic_json&) and friend operator<<(std::ostream&, const basic_json&) instead.Release date: 2019-03-20 SHA-256: d2eeb25d2e95bffeb08ebb7704cdffd2e8fca7113eba9a0b38d60a5c391ea09a (json.hpp), 69cc88207ce91347ea530b227ff0776db82dcb8de6704e1a3d74f4841bc651cf (include.zip)
This release fixes a regression and a bug introduced by the earlier 3.6.0 release. All changes are backward-compatible.
<Windows.h> was included. #1531This release does not deprecate any functions. As an overview, the following functions have been deprecated in earlier versions and will be removed in the next major version (i.e., 4.0.0):
iterator_wrapper are deprecated. Please use the member function items() instead.friend std::istream& operator<<(basic_json&, std::istream&) and friend std::ostream& operator>>(const basic_json&, std::ostream&) are deprecated. Please use friend std::istream& operator>>(std::istream&, basic_json&) and friend operator<<(std::ostream&, const basic_json&) instead.Release date: 2019-03-20 SHA-256: ce9839370f28094c71107c405affb3b08c4a098154988014cbb0800b1c44a831 (json.hpp), 237c5e66e7f8186a02804ce9dbd5f69ce89fe7424ef84adf6142e973bd9532f4 (include.zip)
ℹ️ This release introduced a regression. Please update to version 3.6.1!
This release adds some convenience functions for JSON Pointers, introduces a contains function to check if a key is present in an object, and improves the performance of integer serialization. Furthermore, a lot of small bug fixes and improvements have been made. All changes are backward-compatible.
operator/ and operator/=. JSON Pointers can be inspected with empty, back, and parent_pointer, and manipulated with push_back and pop_back. #1434contains to check whether an element exists in a JSON object with a given key. Returns false when called on non-object types. #1471 #1474JSON_Install to control whether the library should be installed (default: on). #1330nodiscard attribute to meta(), array(), object(), from_cbor, from_msgpack, from_ubjson, from_bson, and parse. #1433This release does not deprecate any functions. As an overview, the following functions have been deprecated in earlier versions and will be removed in the next major version (i.e., 4.0.0):
iterator_wrapper are deprecated. Please use the member function items() instead.friend std::istream& operator<<(basic_json&, std::istream&) and friend std::ostream& operator>>(const basic_json&, std::ostream&) are deprecated. Please use friend std::istream& operator>>(std::istream&, basic_json&) and friend operator<<(std::ostream&, const basic_json&) instead.Release date: 2018-12-22 SHA-256: 8a6dbf3bf01156f438d0ca7e78c2971bca50eec4ca6f0cf59adf3464c43bb9d5 (json.hpp), 3564da9c5b0cf2e032f97c69baedf10ddbc98030c337d0327a215ea72259ea21 (include.zip)
This release introduces the support for structured bindings and reading from FILE*. Besides, a few bugs have been fixed. All changes are backward-compatible.
Structured bindings are now supported for JSON objects and arrays via the items() member function, so finally this code is possible:
for (auto& [key, val] : j.items()) {
std::cout << key << ':' << val << '\n';
}
#1388 #1391
Added support for reading from FILE* to support situations in which streams are nit available or would require too much RAM. #1370 #1392
eofbit was not set for input streams when the end of a stream was reached while parsing. #1340 #1343-Wshadow warning #1346std::snprintf calls to avoid error in MSVC. #1337This release does not deprecate any functions. As an overview, the following functions have been deprecated in earlier versions and will be removed in the next major version (i.e., 4.0.0):
iterator_wrapper are deprecated. Please use the member function items() instead.friend std::istream& operator<<(basic_json&, std::istream&) and friend std::ostream& operator>>(const basic_json&, std::ostream&) are deprecated. Please use friend std::istream& operator>>(std::istream&, basic_json&) and friend operator<<(std::ostream&, const basic_json&) instead.