Try latest C++ standard setting for Visual Studio

Author: d-frey

src/test/json/CMakeLists.txt

@@ -7,7 +7,7 @@ foreach (testsourcefile ${testsources})
   set_property (TARGET ${exename} PROPERTY CXX_EXTENSIONS OFF)
   target_link_libraries (${exename} taocpp::json)
   if (MSVC)
-    target_compile_options (${exename} PRIVATE /W4 /WX /utf-8)
+    target_compile_options (${exename} PRIVATE /std:c++latest /W4 /WX /utf-8)
   else ()
     target_compile_options (${exename} PRIVATE -pedantic -Wall -Wextra -Wshadow -Werror)
   endif ()