size_t和std :: size_t之间的区别 [英] Difference between size_t and std::size_t

问题描述

size_t 和 std :: size_t 之间的区别在于它们的声明位置应该使用和任何其他区别特征？

What are the differences between size_t and std::size_t in terms of where they are declared, when they should be used and any other differentiating features?

推荐答案

C的 size_t C ++的 std :: size_t 都是相同的。

C's size_t and C++'s std::size_t are both same.

在C中，它在< stddef.h> 中定义，在C ++中定义在< cstddef> ，其内容与C头相同（请参阅下面的引文）。 sizeof 运算符的结果中定义无符号整数类型。

In C, it's defined in <stddef.h> and in C++, its defined in <cstddef> whose contents are the same as C header (see the quotation below). Its defined as unsigned integer type of the result of the sizeof operator.

C标准在§17.7/ 2中规定

C Standard says in §17.7/2,

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

size_t是无符号整数类型 sizeof 运算符的结果

And C++ Standard says (about cstddef header) in §18.1/3,

> cstddef header）在§18.1/ 3中，

The contents are the same as the Standard C library header , with the following changes.

内容与标准C库标题 。

唯一的区别是C ++在 std 命名空间中定义 size_t 。 b
$ b

请注意，上面的行还说有以下变化，它不是指 size_t 。它指的是C ++在语言（不存在于C中）中添加的新增内容（大多数），这些内容也在同一个头文件中定义。

Please also notice that the above line also says "with the following changes" which isn't referring to size_t. Its rather referring to the new additions (mostly) made by C++ into the language (not present in C) which are also defined in the same header.

维基百科有关于size_t的范围和存储大小的非常好的信息：

Wikipedia has very good info about range and storage size of size_t:

范围和存储大小size_t

size_t的实际类型是
平台相关 常见错误
是假设size_t与
unsigned int相同，这可能导致
编程错误，[3] [4]移动
从32到64位架构，对于
示例。

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,[3][4] when moving from 32 to 64-bit architecture, for example.

根据1999 ISO C
标准（C99），size_t是unsigned
至少16位的整数类型。

According to the 1999 ISO C standard (C99), size_t is an unsigned integer type of at least 16 bits.

其余的可以从此网页在维基百科。

And the rest you can read from this page at wikipedia.

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