Size_t existence
"Is there some way I can portably check if size_t is around, short of
re-editing your standard #include files to act like the other compilers?"
By definition, there no "portable" way to check if size_t has been defined.
Instead, you should just #include the header file that defines size_t, which is
<stddef.h>. The ANSI (er, ISO) C standard makes no claims about checking to see
if a name is defined.
-phil