Using 'const' in C, what porting trouble might that cause?

Question

I would like to use 'const' in C interface functions to note that certain char * arguments are not modified by the function.

What trouble might this cause in porting this code to various platforms? Is support of 'const' in C code pretty standard? When did this become officially in C standard?

Answer 1

I can't imagine const not being supported by any compilers, so porting should be a non-issue. If you were to find such a beast, you could just put

#define const

Somewhere in a common header file to make all of the const keywords vanish. The runtime semantics of your program won't change at all (since your compiler didn't support the keyword anyway).