Summary

This release introduces a few convenience functions and performs a lot of house keeping (bug fixes and small improvements). All changes are backward-compatible.

New Features

• Add overload of the contains function to check if a JSON pointer is valid without throwing exceptions, just like its counterpart for object keys. #1600
• Add a function to_string to allow for generic conversion to strings. #916 #1585
• Add return value for the emplace_back function, returning a reference to the added element just like C++17 is introducing this for std::vector. #1609
• Add info how to use the library with the pacman package manager on MSYS2. #1670

Bug Fixes

• Fix an issue where typedefs with certain names yielded a compilation error. #1642 #1643
• Fix a conversion to std::string_view in the unit tests. #1634 #1639
• Fix MSVC Debug build. #1536 #1570 #1608
• Fix get_to method to clear existing content before writing. #1511 #1555
• Fix a -Wc++17-extensions warning. nodiscard attributes are now only used with Clang when -std=c++17 is used. #1535 #1551

Improvements

• Switch from Catch to doctest for the unit tests which speeds up compilation and runtime of the 112,112,308 tests.
• Add an explicit section to the README about the frequently addressed topics character encoding, comments in JSON, and the order of object keys.

Further Changes

• Use GNUInstallDirs to set library install directories. #1673
• Fix links in the README. #1620 #1621 #1622 #1623 #1625
• Mention json type on the documentation start page. #1616
• Complete documentation of value() function with respect to type_error.302 exception. #1601
• Fix links in the documentation. #1598
• Add regression tests for MSVC. #1543 #1570
• Use CircleCI for continuous integration.
• Use Doozer for continuous integration on Linux (CentOS, Raspbian, Fedora)
• Add tests to check each CMake flag (JSON_BuildTests, JSON_Install, JSON_MultipleHeaders, JSON_Sanitizer, JSON_Valgrind, JSON_NoExceptions, JSON_Coverage).
• Use Hedley to avoid re-inventing several compiler-agnostic feature macros like 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.
• Build and run tests on AppVeyor in DEBUG and RELEASE mode.

Deprecated functions

This release does not deprecate any functions.