有什么办法获得“当前函数”的返回类型。 [英] Is there any way to get the return type of the "current function"

问题描述

我想写一个模板，它将获得作为参数的函数的返回类型，其中它被实例化。

I would like to write a template that would get as a parameter the return type of the function in which it is being instantiated.

例如， ve 结果模板类：

For example, assume I've a Result templated class:

template<type T>
class Result {
    T _result_value;
    T& operator=( T that );
    ~Result( );
}

这个类会有几个特殊化。在析构函数中，我想记录返回类型，在 operator = 赋值中，我想检查并声明错误值。

There would be several specializations for this class. In the destructor I would like to log the return type, and within the operator= assignment I would like to check and assert for error values.

理想情况下，我想能够有这样的定义：

Ideally, I would like to be able to have such a define:

#define RESULT Result< /* decltype magic for type of current function */ >

所以我可以使用它：

HFILE MyOpenFile( ... ) {
    RESULT result;
}

...将被推导到 HFILE> 。这是一个简单的例子：写 RESULT 而不是结果< HFILE> 不是一个大问题，其他情况下，当前函数的返回类型不容易获得。

...which will be deduced to Result<HFILE>. This is a simplified example: writing RESULT instead of Result<HFILE> isn't a big deal, but there are other scenarios where the return type of the current function isn't easily obtained.

推荐答案

否。 C ++中没有什么是指当前函数。最接近的是 __ func __ 但是这是一个字符串字面量。因此，没有什么可以传递给 decltype 。

No. There's nothing in C++ which refers to the "current function". The closest is __func__ but that's a string literal. Hence, there's nothing to pass to decltype.

不是你需要的， auto 。

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