-ansi -pedantic 64 bits length integers in C

Question

I would like to know if there is an equivalent to int64_t in C that would work on 32 and 64 bits platforms and that is ansi and pedantic gcc modes compliant.

I found this interesting post , but it relates on C++.

I tried to used long long but i get an integer overflow in expression [-WOverflow] error. Moreover long long is not supported by ISO C90.

I also tried what is suggested in this post , but i still have a -WOverflow error with using int64_t

Any solutions ?

Answer 1

• In C89 (required by -ansi flag), there is no standard way to use a 64 bits integer. You have to rely on the types provided by your implementation.

• In C99, some implementations may define int64_t , since it is an optional type. As for long long (C99), there is no guarantee that its width is exactly of 64 bits.