是返回void有效code? [英] Is returning void valid code?
问题描述
我发现下面的code被采用Visual C ++ 2008接受和GCC编译器4.3:
I found out that the following code gets accepted by Visual C++ 2008 and GCC 4.3 compilers:
void foo()
{
}
void bar()
{
return foo();
}
我有点惊讶,它编译。这是一个语言功能,或者是在编译器中的错误?什么的C / C ++标准,说这个?
I am a bit surprised that it compiles. Is this a language feature or is it a bug in the compilers? What do the C/C++ standards say about this?
推荐答案
这是的C语言特征++
It's a language feature of C++
C ++(ISO 14882:2003)6.6.3 / 3
C++ (ISO 14882:2003) 6.6.3/3
,类型为CV作废的前pression的return语句只能与CV无效的返回类型函数中使用;只是在函数返回到其调用者之前的前pression进行评估。
A return statement with an expression of type "cv void" can be used only in functions with a return type of cv void; the expression is evaluated just before the function returns to its caller.
C(ISO 9899:1999)6.8.6.4/1
C (ISO 9899:1999) 6.8.6.4/1
和前pression return语句不得出现在它的返回类型的函数
是无效的。
A return statement with an expression shall not appear in a function whose return type is void.
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