在通用lambda捕获中使用此指针 [英] Using a this pointer in a generic lambda capture

问题描述

我有一个问题，其中Clang（3.6）和G ++（5.1）有不同的意见：

  #include< ;功能> 
 
 struct X 
 {
 X（）
 {
 std :: function< void（int） f = [this]（auto x）{foo（x）;}; 
} 
 
 void foo（int x）{} 
}; 
 
 int main（）{} 
  

Clang接受这一点， ：

 错误：无法调用成员函数'void X :: foo（int）'没有对象
  

如果我调用 this-> foo（x）

注意：lambda签名中的auto和转换为std :: function<>的都是需要触发此情况。

解决方案

如果我调用this-> foo

考虑到它在gcc 5.2中编译，clang是一个正确的您的具体情况。它看起来像只是一个bug在gcc 5.1。

此外，它也有直观的意义，这个

I have an issue in which Clang (3.6) and G++ (5.1) have a differing opinion:

#include <functional>

struct X
{
    X()
    {
        std::function<void (int)> f = [this](auto x){foo(x);};
    }

    void foo(int x){}
};

int main(){}

Clang accepts this, whereas G++ states:

error: cannot call member function ‘void X::foo(int)’ without object

Both compilers accept it if I call this->foo(x) directly instead, but I'd rather know who's right.

Note: both the "auto" in the lambda signature and the conversion to a std::function<> are required to trigger this case.

解决方案

Both compilers accept it if I call this->foo(x) directly instead, but I'd rather know who's right.

Considering it compiles in gcc 5.2, clang is the one correct in your specific case. It looks like it was just a bug in gcc 5.1. gcc 6.0 also compiles this fine.

Plus it makes intuitive sense, this should be implied.

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