函数作为另一个函数错误的参数 - C++

Question

我有以下功能：

CompareType CompareByCitizensNum(const City& c1, const City& c2) {
        if (c1.getNumCitizens() > c2.getNumCitizens()
                || ((c1.getNumCitizens() == c2.getNumCitizens())
                        && (c1.getCityId() > c2.getCityId()))) {
            return BIGGER;
        } else if (c1.getCityId() == c2.getCityId()) {
            return EQUALS;
        }
        return SMALLER;
    }

这是需要使用此功能的方法：

avlTreeVertix(City newKey, avlTreeVertix* fatherToBe,
            CompareType (*compare)(const City&, const City&)) :
            bf(0), key(newKey), RightHigh(0), LeftHigh(0), vertexesInSubTree(1), father(
                    fatherToBe), childL(NULL), childR(
            NULL), compare(compare) {
        CHECK_NULL(father,);
        if (compare(key, father->key) == BIGGER) {
            //if (isGreater(father)) {
            father->childR = this;
        } else {
            father->childL = this;
        }
    }

我尝试通过以下行调用它：

rankTree = new avlTreeVertix(c, NULL, CompareByCitizensNumx);

但是它说：

no matching function for call to wet2::avlTreeVertix::avlTreeVertix(wet2::City&, NULL, <unresolved overloaded function type>)

有什么想法吗？谢谢！

Answer 1

好的伙计们，问题是该函数是一个成员函数，所以我需要在函数声明中添加一个 "static"，现在它可以工作了！骗我..

函数作为另一个函数错误的参数 - C++

function as a parameter to another function error - c++

c++