2016-02-25 32 views
0

我试图创建一个由int和指向成员函数的指针组成的地图。创建成员函数指针的地图

class Factory 
{ 
    public: 
    typedef nts::IComponent *(*createFunction)(const std::string &value); 
    Factory(); 
    ~Factory(); 
    nts::IComponent *createComponent(const std::string &type, const std::string &value); 
    private: 
    nts::IComponent *create4001(const std::string &value) const; 
    nts::IComponent *create4013(const std::string &value) const; 
    nts::IComponent *create4040(const std::string &value) const; 
    nts::IComponent *create4081(const std::string &value) const; 

    std::map<int, createFunction> map = {{4001, Factory::create4001}, 
             {4013, Factory::create4013}, 
             {4040, Factory::create4040}}; 
}; 

但是我有这个以下错误:

includes/Factory.hpp:24:68: error: could not convert ‘{{4001, ((Factory*)this)->Factory::create4001}, {4013, ((Factory*)this)->Factory::create4013}, {4040, ((Factory*)this)->Factory::create4040}}’ from ‘<brace-enclosed initializer list>’ to ‘std::map<int, nts::IComponent* (*)(const std::__cxx11::basic_string<char>&)>’ 
             {4040, Factory::create4040}}; 

有什么想法?

+0

阅读起来在使用它之前,您最喜欢的书中的主题。 'createFunction'不是成员函数指针的别名。它也缺少一个'const'限定符。 – LogicStuff

+1

尝试'使用createFunction = nts :: IComponent *(const std :: string&);',然后使用'std :: map map;'。 –

+0

@KerrekSB相同的错误 –

回答

2

typedef为指针(非静态)成员函数如下:

typedef nts::IComponent *(Factory::*createFunction)(const std::string &value) const; 
//      ^^^^^^^            ^^^^^ 
//     nested name specifier        missing const 

优选方式:

using createFunction = nts::IComponent *(Factory::*)(const std::string &value) const; 

初始化您的地图:

std::map<int, createFunction> map = {{4001, &Factory::create4001}, 
            {4013, &Factory::create4013}, 
            {4040, &Factory::create4040}}; 
//          ^
//      compiler would think you're trying to call 
//      a static function without an argument list