如何真正从类/构造

Question

到目前为止，这是接近回答这个问题的唯一联系是这样的初始化对象的2D矢量： How do I initialize a stl vector of objects who themselves have non-trivial constructors?

不过，我试图做到这一点，我仍然难住它。

相关的代码：

边缘

// Edge Class 
class Edge{ 
    public: 
    // std::string is used to avoid not a name type error 
    Edge (std::string, double); 
    double get_dist(); 
    std::string get_color(); 
    ~Edge(); 
    private: 
    std::string prv_color; // prv_ tags to indicate private 
    double prv_distance; 
}; 

Edge::Edge (std::string color, double distance){ 
    prv_color = color; 
    prv_distance = distance; 
}; 

图

// Graph Class 

class Graph{ 
    public: 
    Graph (double, double); 
    double get_dist_range(); 
    ~Graph(); 

    private: 
    double prv_edge_density; // how many edges connected per node 
    double prv_dist_range; // start from 0 to max distance 
    std::vector < std::vector <Edge*> > nodes; // the proper set-up of 
}; 

// Graph constructor 
Graph::Graph (double density, double max_distance){ 
    prv_edge_density = density; 
    prv_dist_range = max_distance; 
    nodes (50, std::vector <Edge*> (50)); // THIS LINE STUMPS ME MOST 
}; 

当我试图初始化的对象指针的载体，我得到这个错误从以下线路：

nodes (50, std::vector <Edge*> (50)); // Error at this line 

error: no match for call to ‘(std::vector<std::vector<Edge*, std::allocator<Edge*> >, 
    std::allocator<std::vector<Edge*, std::allocator<Edge*> > > >) 
    (int, std::vector<Edge*, std::allocator<Edge*> >)’ 

我希望尽快就此提供建议。

注：假设我已经使用.cpp文件和.h文件分开的代码

Answer 1

您需要了解初始化列表

// Graph constructor 
Graph::Graph (double density, double max_distance) : 
    nodes (50, std::vector <Edge*> (50)) 
{ 
    prv_edge_density = density; 
    prv_dist_range = max_distance; 
} 

未经测试的代码。