:: extend existing pre-defined macros to align with C11

:: pre-defined macros to identify installed features __STDC_*__

:: trivial - currently covered in C++ part - add to align with C99

:: inline functions

:: anonymous structures and unions

** new - add to align with C99 and C++11

::: bool macro, _Bool data type (C99)

::: variadic macros

::: Unicode support – same as C++

::: static assertions – evaluated later than #if and #error

::: bounds-checking – list of safe alternative library functions for robust programming

::: multi-threading support