IBM has made some C99 functions accessible to the XL C++ compiler.
These C99 functions are enabled by the individual LANGLVL or KEYWORD
suboptions.
You can also obtain C99 behavior with the XL C++ compiler by using
the following KEYWORD and LANGLVL suboptions:
- KEYWORD(RESTRICT) or LANGLVL(EXTENDED), which enable the restrict qualifier
for improved aliasing information.
- LANGLVL(UCS), which enables support for valid universal character
name ranges.
- LANGLVL(C99__FUNC__) or LANGLVL(EXTENDED), which enable the __func__ identifier
for debugging assistance.
C++ applications can also access C99 runtime library functions
by using feature test macros. See Feature test macros that control C99 interfaces in XL C++ applications.