如果main为空，D如何在成功时返回0而在失败时返回非零？ [英] How can D return 0 on success and non-zero on failure if main is void?

问题描述

在D中，定义了 main 函数：

void main(/*perhaps some args but I do not remember*/)
{

}  

我确定该函数成功返回零，失败返回非零，但它被定义为不返回任何东西。背后的逻辑是什么？

I know for sure that this function returns zero on success and non-zero on failure and yet it is defined as not returning anything. What is the logic behind it?

推荐答案

具有void返回类型的函数不会返回任何值。当您认为调用堆栈看起来像这样时，没有什么不合逻辑的：

function with void return type does not return any value. There is nothing illogical when you consider call stack looks like this:

OS -> D runtime -> main

D运行时系统调用main函数，该运行时系统认识到main函数不返回任何内容-并且在这种情况下，将成功返回操作系统。如果主函数定义为返回类型int，则D运行时返回主函数返回的OS值。

The main function is invoked by D runtime system, which recognized that the main function returns nothing - and in this case return success to the OS. In case the main function is defined with return type int, then the D runtime return to OS value returned by main function.

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