Is "long" still useful in C?

Question

• It's not the largest integer type anymore now that there's "long long".
• It's not a fixed-width type: It's 32 bits on some platforms and 64 on others.
• It's not necessarily the same size as a pointer (for example, on 64-bit Windows)

So, does "long" have any meaning anymore? Is there ever a reason to declare a long instead of a ptrdiff_t or int64_t?

Answer 1

Is there ever a reason to declare a long instead of a ptrdiff_t or int64_t?

There never was in those cases. If you want a pointer difference, or a specifically 64-bit value, you should be using ptrdiff_t or int64_t. You should never have been using long in the first place, except maybe behind a platform-dependent typedef.

You should use long when you need at least a 32-bit integer, because int is only guaranteed to be at least 16 bits. If you need a native type, but need at least 32-bits, use long. If the 16-bit limitation is acceptable on some old platforms (that probably don't matter and your code probably won't be compiled on ever) then it doesn't particularly matter.