为什么 main 的默认返回值为 0 而不是 EXIT_SUCCESS?

2022-01-19 00:00:00 return main standards c++

ISO 1998 c++ 标准规定在 main 中不显式使用 return 语句等同于使用 return 0.但是如果一个实现有不同的标准无错误"代码，例如 -1?

The ISO 1998 c++ standard specifies that not explicitly using a return statement in the main is equivalent to use return 0. But what if an implementation has a different standard "no error" code, for example -1?

为什么不使用标准宏 EXIT_SUCCESS 将被 0 或 -1 或任何其他值替换，具体取决于实现?

Why not use the standard macro EXIT_SUCCESS that would be replaced either by 0 or -1 or any other value depending on the implementation?

C++ 似乎强加了程序的语义，这不是只应描述程序行为方式的语言的角色.此外，错误"返回值的情况有所不同:只有 EXIT_FAILURE 是标准的错误"终止标志，没有明确的值，例如1".

C++ seems to force the semantic of the program, which is not the role of a language which should only describe how the program behaves. Moreover the situation is different for the "error" return value: only EXIT_FAILURE is a standard "error" termination flag, with no explicit value, like "1" for example.

这些选择的原因是什么?

What are the reasons of these choices?

推荐答案

从 main() 返回零与您所要求的基本相同.从 main() 返回零不必将零返回到主机环境.

Returning zero from main() does essentially the same as what you're asking. Returning zero from main() does not have to return zero to the host environment.

来自 C90/C99/C++98 标准文档:

From the C90/C99/C++98 standard document:

如果status的值为0或EXIT_SUCCESS，则返回成功终止的实现定义形式.

If the value of status is zero or EXIT_SUCCESS, an implementation-defined form of the status successful termination is returned.

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