c++ - 在哪里可以找到 size_t 的定义？

Question

我看到用这种类型定义的变量，但我不知道它来自哪里，也不知道它的目的是什么。为什么不使用 int 或 unsigned int ？ (其他“类似”类型呢？Void_t 等)。

Answer 1

来自Wikipedia

The stdlib.h and stddef.h header files define a datatype called size_t1 which is used to represent the size of an object. Library functions that take sizes expect them to be of type size_t, and the sizeof operator evaluates to size_t.

The actual type of size_t is platform-dependent; a common mistake is to assume size_t is the same as unsigned int, which can lead to programming errors,2 particularly as 64-bit architectures become more prevalent.

来自C99 7.17.1/2

The following types and macros are defined in the standard header stddef.h

<snip>

size_t

which is the unsigned integer type of the result of the sizeof operator