int64_t 的定义

Definition of int64_t(int64_t 的定义)

问题描述

我是 C/C++ 新手，所以我有几个关于基本类型的问题:

I am new to C/C++, so I have a couple of questions about a basic type:

a) 你能解释一下 int64_t 和 long (long int) 的区别吗?据我了解，两者都是 64 位整数.有什么理由选择其中一个吗?

a) Can you explain to me the difference between int64_t and long (long int)? In my understanding, both are 64 bit integers. Is there any reason to choose one over the other?

b) 我试图在网上查找 int64_t 的定义，但没有成功.有没有我需要咨询这些问题的权威来源?

b) I tried to look up the definition of int64_t on the web, without much success. Is there an authoritative source I need to consult for such questions?

c) 对于使用 int64_t 编译的代码，我目前包括 ，这对我来说没有多大意义.是否有其他包含提供 int64_t 的声明?

c) For code using int64_t to compile, I am currently including <iostream>, which doesn't make much sense to me. Are there other includes that provide a declaration of int64_t?

推荐答案

a) 你能解释一下 int64_t 和 long (long int) 的区别吗?据我了解，两者都是 64 位整数.有什么理由选择其中一个吗?

a) Can you explain to me the difference between int64_t and long (long int)? In my understanding, both are 64 bit integers. Is there any reason to choose one over the other?

前者是有​​符号整数类型，正好 64 位.后者是至少 32 位的有符号整数类型.

The former is a signed integer type with exactly 64 bits. The latter is a signed integer type with at least 32 bits.

b) 我试图在网上查找 int64_t 的定义，但没有成功.有没有我需要咨询这些问题的权威来源?

b) I tried to look up the definition of int64_t on the web, without much success. Is there an authoritative source I need to consult for such questions?

http://cppreference.com 在这里介绍:http://en.cppreference.com/w/cpp/types/integer.然而，权威来源是 C++ 标准(这个特定的位可以在 §18.4 整数类型 [cstdint] 中找到).

http://cppreference.com covers this here: http://en.cppreference.com/w/cpp/types/integer. The authoritative source, however, is the C++ standard (this particular bit can be found in §18.4 Integer types [cstdint]).

c) 对于使用 int64_t 编译的代码，我包括 ，这对我来说没有多大意义.是否有其他包含提供 int64_t 的声明?

c) For code using int64_t to compile, I am including <iostream>, which doesn't make much sense to me. Are there other includes that provide a declaration of int64_t?

在 或 (在命名空间 std 下)或 中声明.stdint.h> 或 <inttypes.h>(在全局命名空间中).