lambdas 需要捕获“this"来调用静态成员函数?

2021-12-23 00:00:00 lambda c++ c++11

对于以下代码:

struct B
{
    void g()
    {
        []() { B::f(); }();
    }

    static void f();
};

g++ 4.6 给出错误:

g++ 4.6 gives the error:

test.cpp:在 lambda 函数中:
test.cpp:44:21: 错误:此 lambda 函数未捕获this"

test.cpp: In lambda function:
test.cpp:44:21: error: 'this' was not captured for this lambda function

(有趣的是，g++ 4.5 编译代码很好).

(Interestingly, g++ 4.5 compiles the code fine).

这是 g++ 4.6 中的错误，还是真的有必要捕获this"参数才能调用静态成员函数?我不明白为什么会这样，我什至用 B:: 限定了调用.

Is this a bug in g++ 4.6, or is it really necessary to capture the 'this' parameter to be able to call a static member function? I don't see why it should be, I even qualified the call with B::.

推荐答案

我同意，它应该编译得很好.对于修复(如果您还不知道)，只需添加引用捕获，它就会在 gcc 4.6 上正常编译

I agree, it should compile just fine. For the fix (if you didn't know already), just add the reference capture and it will compile fine on gcc 4.6

struct B
{
    void g()
    {
        [&]() { B::f(); }();
    }

    static void f() { std::cout << "Hello World" << std::endl; };
};

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