尝试插入集合(c ++)时,'operator <'不匹配？

struct MyStruct {
    int value;
    bool operator<(const MyStruct& other) const {
        return value < other.value;
    }
};

std::set<MyStruct> mySet;

struct MyStruct {
    int value;
};

bool compareMyStruct(const MyStruct& a, const MyStruct& b) {
    return a.value < b.value;
}

std::set<MyStruct, decltype(compareMyStruct)*> mySet(compareMyStruct);

struct CompareMyStruct {
    bool operator()(const MyStruct& a, const MyStruct& b) const {
        return a.value < b.value;
    }
};

std::set<MyStruct, CompareMyStruct> mySet;