What is the difference between passing sbrk() an intptr_t vs int in C

It seems to have no impact on the functionality of sb开发者_运维问答rk, but in sbrk()'s documentation it says that it requires an intptr_t parameter.

It works (or at least seems to work) when passing an int type as a parameter.

This is in regular C.

intptr_t changes size depending on the architecture. int may or may not change size depending on the architecture- that is, if you are on 64bit, then intptr_t MUST be 64bits, whereas int may be 32bits.

As long as the right header is included, you're not passing an int to sbrk(). The value you are passing is converted to intptr_t according to C promotion rules. These rules are terribly subtle so you should at least know they exist and avoid invoking them in corner cases.

As a consequence, do not expect something spectacular such as a crash, when you pass sbrk something that looks to you like an int, even if intptr_t is different from int on your platform, as long as the header that provides sbrk()'s prototype is included.