C ++类向量推回错误

Question

我是C ++的新手，我使用的是G ++编译器（Ubuntu 4.8.1-2ubuntu1~12.04）4.8.1
我尝试实现无向wieghted Graph。由两个类Edges和Graph组成。但是编译器给了我这个错误

编译器提供此错误

  

/ usr / include / c ++ / 4.8 / ext / new_allocator.h：实例化'void __gnu_cxx :: new_allocator＆lt; _Tp＆gt; :: construct（_Up *，_ Args＆amp;＆amp; ...）   [与_Up = UNDIR_W_EDGE; _Args = {const UNDIR_W_EDGE＆amp;}; _Tp =   UNDIR_W_EDGE]“：       /usr/include/c++/4.8/bits/alloc_traits.h:254:4：从'static typename中获取   的std :: enable_ifAlloc＆GT; :: _ construct_helper＆LT; _TP，   _Args＆gt; :: value，void＆gt; :: type std :: allocator_traits＆lt; _Alloc＆gt; :: _ S_construct（_Alloc＆amp;，_Tp *，_ Args＆amp;＆amp;   ......）[与_Tp = UNDIR_W_EDGE; _Args = {const UNDIR_W_EDGE＆amp;}; _Alloc =   的std ::分配器;类型名   的std :: enable_ifAlloc＆GT; :: _ construct_helper＆LT; _TP，   _Args＆gt; :: value，void＆gt; :: type = void]'       /usr/include/c++/4.8/bits/alloc_traits.h:393:57：从'static decltype（_S_construct（__ a，__ p，   （正向＆LT; _args＆GT）（标准:: allocator_traits ::构造:: __参数）...））   std :: allocator_traits＆lt; _Alloc＆gt; :: construct（_Alloc＆amp;，_Tp *，_ Args＆amp;＆amp; ...）   [与_Tp = UNDIR_W_EDGE; _Args = {const UNDIR_W_EDGE＆amp;}; _Alloc =   的std ::分配器; decltype（_S_construct（__ a，__ p，   （forward＆lt; _Args＆gt;）（std :: allocator_traits :: construct :: __ args）...））=   ]”       /usr/include/c++/4.8/bits/stl_vector.h:906:34：需要来自'void std :: vector＆lt; _Tp，_Alloc＆gt; :: push_back（const value_type＆amp;）[with _Tp   = UNDIR_W_EDGE; _Alloc = std :: allocator; std :: vector＆lt; _Tp，_Alloc＆gt; :: value_type = UNDIR_W_EDGE]'       ../src/GRAPH.h:31:5：需要'void GRAPH :: addEdge（const Edge＆amp;）[with Edge = UNDIR_W_EDGE]'       ../src/main.cpp:32:13：从这里要求       /usr/include/c++/4.8/ext/new_allocator.h:120:4：错误：没有匹配函数来调用'UNDIR_W_EDGE :: UNDIR_W_EDGE（const UNDIR_W_EDGE＆amp;）'       {:: new（（void *）__ p）_Up（std :: forward＆lt; Args＆gt;（ _args）...）; }

守则

GRAPH.h文件

#include "vector"

template <typename Edge>
class GRAPH {
 private:
 // Implementation-dependent code
int Vcnt;
int Ecnt;
std::vector<std::vector< Edge > > adj;
 public:
GRAPH(int x):Vcnt(x),Ecnt(0) {

    adj.resize(Vcnt);
}
 virtual ~GRAPH();
 virtual int V() const;
 virtual int E() const;
 virtual void addEdge(const Edge &e){
    adj[e.V()].push_back(e);
    adj[e.W()].push_back(e);
    Ecnt++;
 };
 virtual std::vector< Edge > adjIterator(int) const;
};

UNDIRWEDGE.h文件

 class UNDIR_W_EDGE {
    int v,w;
    float weight;

    public:
     UNDIR_W_EDGE(int v, int w, float weight);
     UNDIR_W_EDGE(UNDIR_W_EDGE &);
     virtual ~UNDIR_W_EDGE();
     virtual int V()const;
     virtual int W()const;
     virtual float WEIGHT()const;
     virtual int CompareTo(UNDIR_W_EDGE e)const;
    };

UNDIRWEDGE.cpp 中的

inline int UNDIR_W_EDGE::CompareTo(UNDIR_W_EDGE e)const{
if(this->weight > e.weight) return 1;
else if (this->weight < e.weight)return -1;
else                            return 0;
}  

在main.cpp

中

GRAPH<UNDIR_W_EDGE> g(10);
UNDIR_W_EDGE e(0,7,0.0);
g.addEdge(e);

Answer 1

您没有UNDIR_W_EDGE的复制构造函数。

std::vector<UNDIR_W_EDGE>内部以及CompareTo中需要复制构造函数，后者按值（由于某种原因）获取其参数。

你做有这个：

UNDIR_W_EDGE(UNDIR_W_EDGE &);

据推测，你打算这样做：

UNDIR_W_EDGE(const UNDIR_W_EDGE&);