On 22 August 2013 10:58, Roberto E. Vargas Caballero <k...@shike2.com> wrote: > > Since r is a local variable doesn't matter if > the function modifies it (and even is better modify it instead of > using other local variable for it). I use const only when I want > show that the function is going to accept constant string which > should not be modified, like for example: > > printf(const char *fmt, ...) >
This is true; implementation-wise on x86-64, local variables are stored in registers and in low-register architectures, like the i386 - it's on the stack (local variables from parameters). As far as I know, in all cases of modern hardware, it's more beneficial to lift the const restriction. Of course, a 'good' compiler would see both versions (const and non-const) and generate the most optimal code :) . The only conceivable use in that context is if you were doing some form of design-by-contract. However, in that case I'd suggest that C isn't the right language to use if that was the intention. Cheers, Ralph -- Tai Chi Minh Ralph Eastwood tcmreastw...@gmail.com
