c++ - "No matching function for call to... unresolved overloaded function type"

Answer 1

如果有人感兴趣，下面是一个可行的解决方案。然而，有重要的代码重复，我担心我无法避免它......

#include <iostream>
#include <vector>
#include <cstdlib>
#include <functional>

using namespace std;


template<typename T,typename D> T fcn_default(const D &obj, const T &phit){
    return 3.2 + phit;
}

template<typename T> class Parent{
    public:
        Parent() {}
        virtual T do_something (const T &phit) const = 0;

};

template<typename T> class Child1 : public Parent<T>{
    public:
        Child1() {
            fcn_ptr = &fcn_default< T , Child1<T> >;
        }
        std::function<T(const Child1<T> &, const T &)> fcn_ptr;

        T do_something(const T &phit) const {
            return (*this).fcn_ptr(*this,phit);
        }
};

template<typename T> class Child2 : public Parent<T>{
    public:
        Child2() {
            fcn_ptr = &fcn_default< T , Child2<T> >;
        }
        std::function<T(const Child2<T> &, const T &)> fcn_ptr;

        T do_something(const T &phit) const {
            return (*this).fcn_ptr(*this,phit);
        }

        T param2;
};



template<typename T> T fcn_mod1   (const Child1<T> &obj, const T &phit){
    return 1.2 + phit;
}
template<typename T> T fcn_mod2   (const Child2<T> &obj, const T &phit){
    return 2.2 + phit + obj.param2*0.001;
}



typedef double lrtType;

int main(){
    std::vector< Parent<lrtType> * > objects;

    Child1<lrtType> *test11 = new Child1<lrtType>();
    objects.push_back(test11);

    Child1<lrtType> *test12 = new Child1<lrtType>();
    test12->fcn_ptr = &fcn_mod1<lrtType>;
    objects.push_back(test12);

    Child2<lrtType> *test2 = new Child2<lrtType>();
    test2->fcn_ptr = &fcn_mod2<lrtType>;
    test2->param2 = 4;
    objects.push_back(test2);

    for (size_t i = 0; i < objects.size(); ++i) {
        std::cout << objects[i]->do_something(2) << std::endl;
    }

    std::cout << "test" << std::endl;
}