模板类无法识别模板参数

时间:2015-04-13 02:54:39

标签: c++ templates compilation g++4.8

我正在尝试编译以下代码。但是,由于某种原因,编译失败了。有许多错误,但所有错误都与模板中的TYPE有关。

我已经检查了代码,它看起来像。我看不出问题。 这可能是一个愚蠢的错误,但没有看到。有人可以帮忙吗?

头文件:

namespace rca {

template<class ContainerType>
class SteinerTreeObserver {

public:
    SteinerTreeObserver();
    SteinerTreeObserver(ContainerType & ec, STTree & st, int);

    void set_steiner_tree (STTree &st, int);
    STTree & get_steiner_tree ();

    void set_container (ContainerType & ec);
    ContainerType & get_container ();

    bool add_edge (int, int, int, int);

    void prunning (int, int);

private:
      ContainerType m_ec;
      STTree m_st;  
      DisjointSet2 dset;

};

};

这是cpp文件:

#include "steiner_tree_observer.h"

using namespace rca;

template<class ContainerType>
SteinerTreeObserver<ContainerType>::SteinerTreeObserver(){}

SteinerTreeObserver<ContainerType>::SteinerTreeObserver(ContainerType & ec,STTree & st,int nodes){}

template<class ContainerType>
void SteinerTreeObserver<ContainerType>::set_steiner_tree (STTree & st, int nodes){}

template<class ContainerType>
STTree & SteinerTreeObserver<ContainerType>::get_steiner_tree ()
{ return m_st;}

void SteinerTreeObserver<ContainerType>::set_container (ContainerType & ec) 
{}

ContainerType & SteinerTreeObserver<ContainerType>::get_container () 
{return m_ec;}

template<class ContainerType>
bool SteinerTreeObserver<ContainerType>::add_edge (int x, 
                                               int y, 
                                               int cost, 
                                               int band_usage)
{ return true;}


template<class ContainerType>
void SteinerTreeObserver<ContainerType>::prunning (int rest, int band)
{}

template class SteinerTreeObserver<EdgeContainer<Comparator, HCell>>;

输出:

steiner_tree_observer.cpp: At global scope:
steiner_tree_observer.cpp:10:21: error: ‘ContainerType’ was not declared in this scope
SteinerTreeObserver<ContainerType>::SteinerTreeObserver(ContainerType & ec,STTree & st,int nodes)
                 ^
steiner_tree_observer.cpp:10:34: error: template argument 1 is invalid
SteinerTreeObserver<ContainerType>::SteinerTreeObserver(ContainerType & ec,STTree & st,int nodes)
                              ^
steiner_tree_observer.cpp:10:56: error: invalid type in declaration before ‘(’ token
SteinerTreeObserver<ContainerType>::SteinerTreeObserver(ContainerType & ec,STTree & st,int nodes)
                                                    ^
steiner_tree_observer.cpp:10:57: error: ‘ContainerType’ was not declared in this scope
SteinerTreeObserver<ContainerType>::SteinerTreeObserver(ContainerType & ec,STTree & st,int nodes)
                                                     ^
steiner_tree_observer.cpp:10:73: error: ‘ec’ was not declared in this scope
SteinerTreeObserver<ContainerType>::SteinerTreeObserver(ContainerType & ec,STTree & st,int nodes)
                                                                         ^
steiner_tree_observer.cpp:10:83: error: expected primary-expression before ‘&’ token
SteinerTreeObserver<ContainerType>::SteinerTreeObserver(ContainerType & ec,STTree & st,int nodes)
                                                                                ^
steiner_tree_observer.cpp:10:85: error: ‘st’ was not declared in this scope
SteinerTreeObserver<ContainerType>::SteinerTreeObserver(ContainerType & ec,STTree & st,int nodes)
                                                                                  ^
steiner_tree_observer.cpp:10:88: error: expected primary-expression before ‘int’
SteinerTreeObserver<ContainerType>::SteinerTreeObserver(ContainerType & ec,STTree & st,int nodes)
                                                                                    ^
steiner_tree_observer.cpp:10:97: error: expression list treated as compound expression in initializer [-fpermissive]
SteinerTreeObserver<ContainerType>::SteinerTreeObserver(ContainerType & ec,STTree & st,int nodes)
                                                                                             ^
steiner_tree_observer.cpp:11:1: error: expected ‘,’ or ‘;’ before ‘{’ token {

steiner_tree_observer.cpp:18:25: error: expected initializer before ‘<’ token
void SteinerTreeObserver<ContainerType>::set_steiner_tree (STTree & st, int nodes)
                       ^
steiner_tree_observer.cpp:25:29: error: expected initializer before ‘<’ token
STTree & SteinerTreeObserver<ContainerType>::get_steiner_tree ()
                           ^
steiner_tree_observer.cpp:30:25: error: expected initializer before ‘<’ token
void SteinerTreeObserver<ContainerType>::set_container (ContainerType & ec) 
                        ^
steiner_tree_observer.cpp:35:1: error: ‘ContainerType’ does not name a type
ContainerType & SteinerTreeObserver<ContainerType>::get_container () 
 ^
steiner_tree_observer.cpp:41:25: error: expected initializer before ‘<’ token
bool SteinerTreeObserver<ContainerType>::add_edge (int x, 
                     ^
steiner_tree_observer.cpp:64:25: error: expected initializer before ‘<’ token
void SteinerTreeObserver<ContainerType>::prunning (int rest, int band)

1 个答案:

答案 0 :(得分:0)

行。但我已经在CPP文件中进行了明确的实例化。那么什么是错的? - Romerito 3小时前 您在哪里进行了明确的实例化?

您必须在标题中包含您的cpp(#include“steiner_tree_observer.cpp”)并将其从构建中排除,并从标题中删除“#include”steiner_tree_observer.h“”。这是因为模板函数定义在实例化时必须已知,而非非模板函数/类。

顺便说一下。如果导出该类,则模板类的显式实例化才有意义。因此,您可以确定,您的链接器将从您编译的DLL或Lib中取出符号。