c++ - 在“结构”中包含“集合”

我试图在结构中包含一个集合，但是这样做时我不知道如何将回调比较函数传递给集合构造函数。

这是我尝试过的基本示例：

struct pointT {
    int x;
    int y;
};

struct pathT{
    Stack<pointT> pointsInPath;
    Set<pointT> pointsIncluded; // need callback here?
};

// Tried this.
//struct pathT{
    //Stack<pointT> pointsInPath;
    //Set<pointT> pointsIncluded(ComparePoints); //doesn't work of course
//};


//Callback function to compare set of points.
int ComparePoints(pointT firstPoint, pointT secondPoint){

    if (firstPoint.x == secondPoint.x && firstPoint.y == secondPoint.y) return 0;
    if (firstPoint.x < secondPoint.x) return -1;
    else return 1;
}


int main() {

    Set<pointT> setOfPoints(ComparePoints); // this works fine
    //pathT allPaths; // not sure how to assign call back function here to a set inside a struct

    return 0;
}

最佳答案

您在c ++中的结构自动是一个类。

因此，您可以提供一个构造函数

struct pathT {
    public:
    pathT();

    private:
    Stack<pointT> pointsInPath;
    Set<pointT> pointsIncluded;
};

pathT::pathT()
: pointsIncluded(ComparePoints)
{

}

问候