Support of replacing assert with something else

[Anton-V-K]

The library uses assert in certain places to signal about fatal errors.
An example:

    void assert_invariant() const noexcept
    {
        assert(m_type != value_t::object or m_value.object != nullptr);
        assert(m_type != value_t::array or m_value.array != nullptr);
        assert(m_type != value_t::string or m_value.string != nullptr);
        assert(m_type != value_t::binary or m_value.binary != nullptr);
    }

Such kind of signal isn't friendly (when debugging, the code just crashes) if compared to _ASSERT (from <crtdbg.h>, which is available for Microsoft C++ compiler) or similar macros (like https://github.com/foonathan/debug_assert).
Please, provide a way to use another macro instead of assert.

It is not possible to globally redefine assert for the library, because it includes <cassert> directly.

Which compiler and operating system are you using?

• Compiler: Microsoft C++ compiler
• Operating system: Windows 7 64-bit

Which version of the library did you use?

• latest release version 3.7.3
• other release - please state the version: ___
• the develop branch

[nlohmann]

Thanks for reporting. I think using a macro like JSON_ASSERT than can be redefined by client code should be possible. I will have a look.

[nlohmann]

See #2242. Feedback welcome!

[nlohmann]

The feature has now been merged to the develop branch and will be part of the next release.