C_STD_VERSION
The C standard version the code is compiling against, it's normally defined with the same value of __STDC_VERSION__
for C standard compatible compilers, while it uses the lowest standard version in pure MSVC, given that in such compiler the definition depends on a compilation flag.
This is granted to be undefined when compiling with a C++ compiler.
See also: %G_C_STD_CHECK_VERSION and %G_CXX_STD_VERSION
Since
2.76