Question

Consider:

int testfunc1 (const int a) {   return a; }  int testfunc2 (int const a) {   return a; } 

Are these two functions the same in every aspect or is there a difference?

I’m interested in an answer for the C language, but if there is something interesting in the C++ language, I’d like to know as well.

Answer 1

const T and T const are identical. With pointer types it becomes more complicated:

1. const char* is a pointer to a constant char
2. char const* is a pointer to a constant char
3. char* const is a constant pointer to a (mutable) char

In other words, (1) and (2) are identical. The only way of making the pointer (rather than the pointee) const is to use a suffix-const.

This is why many people prefer to always put const to the right side of the type (“East const” style): it makes its location relative to the type consistent and easy to remember (it also anecdotally seems to make it easier to teach to beginners).