捕获访问成员函数所需的权限？ [英] Capturing this required to access member functions?

问题描述

我在类的成员函数的局部变量上使用 std :: for_each 循环。我想从for_each中的lambda调用同一类的另一个成员函数。以下是我要执行的操作的简化示例：

I am using a std::for_each loop on a local variable of a member function of a class. I would like to call another member function of that same class from the lambda in the for_each. Below is a simplified example of what I'm trying to do:

void some_class::another_function()
{
    cout << "error";
}
void some_class::some_function( function<bool(const int)> &f)
{
    vector<int> local_variable = {0,0,0,1,1,3,5,43};

    std::for_each( local_variable.begin(), local_variable.end(),
            [&f](const int item)
            {
                if( !f(item) )
                    another_function();
            }
}

GCC 4.6告诉我这个没有被捕获（所以我应该这样做）。那是最好的解决方案吗？或者我应该只捕获我需要的那些功能？ （但这对于较大的结构可能会比较混乱）？

GCC 4.6 is telling me that this isn't captured (so I should do that). Is that the best solution? Or should I only capture those functions I need (but that could be messy for larger constructs)?

推荐答案

GCC是正确的：在 this ，您必须捕获 this 如果成员函数不依赖于数据成员，则将其设为静态，然后您无需捕获此。

GCC is right: to call member functions on this from inside a lambda, you must capture this. If the member function does not depend on the data members, make it static, and then you do not need to capture this.

您无法捕获函数，只能捕获局部变量（包括参数和 this ，但不能捕获特定的数据成员）。

You cannot capture "functions", only local variables (including parameters and this, but not specific data members).

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