问如何调用函数指针数组中的函数？

EN

class myClass {
    int plusOne(int val) {return val + 1;}
    int minusOne(int val) {return val - 1;}
    int keepTheSame(int val) {return val;}

    int (myClass::*functions[3])(int val) {&myClass::plusOne, &myClass::minusOne, &myClass::keepTheSame};

    // Get coordinates of all positions that flip when placing disc at x,y
    vector<pair<int, int>> getFlipDiscs(pair<int, int> moveCoord, int color) {
        int a = (*functions[0])(2); // error: indirection requires pointer operand
    }
};