Merge branch 'develop' into bon8

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

tests/CMakeLists.txt

@@ -80,7 +80,10 @@ target_compile_options(test_main PUBLIC
     #                              std::allocator_traits<...>::construct for the custom-base-class
     #                              test's map type past VS2015's limit. The name is only used for
     #                              debug info, so truncation does not affect the build.
-    $<$<CXX_COMPILER_ID:MSVC>:/W4;/wd4566;/wd4996;/wd4702;/wd4503>
+    #       Disable warning C5285: cannot declare a specialization for 'std::tuple'; MSVC 19.51
+    #                              reports the forward declarations of standard library
+    #                              templates in the vendored doctest.h
+    $<$<CXX_COMPILER_ID:MSVC>:/W4;/wd4566;/wd4996;/wd4702;/wd4503;/wd5285>
     # https://github.com/nlohmann/json/issues/1114
     $<$<CXX_COMPILER_ID:MSVC>:/bigobj> $<$<BOOL:${MINGW}>:-Wa,-mbig-obj>