c++ - 使用标准集时的一些问题

Question

所有，我已经创建了以下代码:

struct Styles{
wstring styleVal;
wstring styleName;
};
set<Styles> vtrStyles1;//filled in somehow
set<Styles> vtrStyles2;//filled in somehow

set<Styles> vtrStyles3(vtrStyles1);
vtrStyles3.insert(vtrStyles2.begin(), vtrStyles2.end());
unCommon = vtrStyles1.size() + vtrStyles2.size() - vtrStyles3.size();

我在 stdafx.h 中包含了 set，并使用了 namespace std；但我收到以下错误:

1>XMLDOMFromVCDlg.cpp(5377): error C2065: 'set' : undeclared identifier
1>XMLDOMFromVCDlg.cpp(5377): error C2275: 'Styles' : illegal use of this type as an expression
1>          XMLDOMFromVCDlg.cpp(5344) : see declaration of 'Styles'
1>XMLDOMFromVCDlg.cpp(5377): error C2065: 'vtrStyles1' : undeclared identifier
1>XMLDOMFromVCDlg.cpp(5378): error C2065: 'set' : undeclared identifier
1>XMLDOMFromVCDlg.cpp(5378): error C2275: 'Styles' : illegal use of this type as an expression
1>          XMLDOMFromVCDlg.cpp(5344) : see declaration of 'Styles'
1>XMLDOMFromVCDlg.cpp(5378): error C2065: 'vtrStyles2' : undeclared identifier
1>XMLDOMFromVCDlg.cpp(5497): error C2065: 'vtrStyles1' : undeclared identifier
1>XMLDOMFromVCDlg.cpp(5497): error C2228: left of '.insert' must have class/struct/union
1>          type is ''unknown-type''
1>XMLDOMFromVCDlg.cpp(5507): error C2065: 'vtrStyles1' : undeclared identifier
1>XMLDOMFromVCDlg.cpp(5507): error C2228: left of '.insert' must have class/struct/union
1>          type is ''unknown-type''
1>XMLDOMFromVCDlg.cpp(5517): error C2065: 'vtrStyles1' : undeclared identifier
1>XMLDOMFromVCDlg.cpp(5517): error C2228: left of '.insert' must have class/struct/union
1>          type is ''unknown-type''
1>XMLDOMFromVCDlg.cpp(5534): error C2065: 'vtrStyles1' : undeclared identifier
1>XMLDOMFromVCDlg.cpp(5534): error C2228: left of '.insert' must have class/struct/union
1>          type is ''unknown-type''
1>XMLDOMFromVCDlg.cpp(5545): error C2065: 'vtrStyles1' : undeclared identifier
1>XMLDOMFromVCDlg.cpp(5545): error C2228: left of '.insert' must have class/struct/union
1>          type is ''unknown-type''
1>XMLDOMFromVCDlg.cpp(5555): error C2065: 'vtrStyles1' : undeclared identifier
1>XMLDOMFromVCDlg.cpp(5555): error C2228: left of '.insert' must have class/struct/union
1>          type is ''unknown-type''
1>XMLDOMFromVCDlg.cpp(5565): error C2065: 'vtrStyles1' : undeclared identifier
1>XMLDOMFromVCDlg.cpp(5565): error C2228: left of '.insert' must have class/struct/union
1>          type is ''unknown-type''
1>XMLDOMFromVCDlg.cpp(5606): error C2065: 'vtrStyles2' : undeclared identifier
1>XMLDOMFromVCDlg.cpp(5606): error C2228: left of '.insert' must have class/struct/union
1>          type is ''unknown-type''
1>XMLDOMFromVCDlg.cpp(5616): error C2065: 'vtrStyles2' : undeclared identifier
1>XMLDOMFromVCDlg.cpp(5616): error C2228: left of '.insert' must have class/struct/union
1>          type is ''unknown-type''
1>XMLDOMFromVCDlg.cpp(5626): error C2065: 'vtrStyles2' : undeclared identifier
1>XMLDOMFromVCDlg.cpp(5626): error C2228: left of '.insert' must have class/struct/union
1>          type is ''unknown-type''
1>XMLDOMFromVCDlg.cpp(5643): error C2065: 'vtrStyles2' : undeclared identifier
1>XMLDOMFromVCDlg.cpp(5643): error C2228: left of '.insert' must have class/struct/union
1>          type is ''unknown-type''
1>XMLDOMFromVCDlg.cpp(5654): error C2065: 'vtrStyles2' : undeclared identifier
1>XMLDOMFromVCDlg.cpp(5654): error C2228: left of '.insert' must have class/struct/union
1>          type is ''unknown-type''
1>XMLDOMFromVCDlg.cpp(5664): error C2065: 'vtrStyles2' : undeclared identifier
1>XMLDOMFromVCDlg.cpp(5664): error C2228: left of '.insert' must have class/struct/union
1>          type is ''unknown-type''
1>XMLDOMFromVCDlg.cpp(5674): error C2065: 'vtrStyles2' : undeclared identifier
1>XMLDOMFromVCDlg.cpp(5674): error C2228: left of '.insert' must have class/struct/union
1>          type is ''unknown-type''
1>XMLDOMFromVCDlg.cpp(5704): error C2065: 'set' : undeclared identifier
1>XMLDOMFromVCDlg.cpp(5704): error C2275: 'Styles' : illegal use of this type as an expression
1>          XMLDOMFromVCDlg.cpp(5344) : see declaration of 'Styles'
1>XMLDOMFromVCDlg.cpp(5704): error C2065: 'vtrStyles1' : undeclared identifier
1>XMLDOMFromVCDlg.cpp(5704): error C3861: 'vtrStyles3': identifier not found
1>XMLDOMFromVCDlg.cpp(5705): error C2065: 'vtrStyles3' : undeclared identifier
1>XMLDOMFromVCDlg.cpp(5705): error C2228: left of '.insert' must have class/struct/union
1>          type is ''unknown-type''
1>XMLDOMFromVCDlg.cpp(5705): error C2065: 'vtrStyles2' : undeclared identifier
1>XMLDOMFromVCDlg.cpp(5705): error C2228: left of '.begin' must have class/struct/union
1>          type is ''unknown-type''
1>XMLDOMFromVCDlg.cpp(5705): error C2065: 'vtrStyles2' : undeclared identifier
1>XMLDOMFromVCDlg.cpp(5705): error C2228: left of '.end' must have class/struct/union
1>          type is ''unknown-type''
1>XMLDOMFromVCDlg.cpp(5706): error C2065: 'vtrStyles1' : undeclared identifier
1>XMLDOMFromVCDlg.cpp(5706): error C2228: left of '.size' must have class/struct/union
1>          type is ''unknown-type''
1>XMLDOMFromVCDlg.cpp(5706): error C2065: 'vtrStyles2' : undeclared identifier
1>XMLDOMFromVCDlg.cpp(5706): error C2228: left of '.size' must have class/struct/union
1>          type is ''unknown-type''
1>XMLDOMFromVCDlg.cpp(5706): error C2065: 'vtrStyles3' : undeclared identifier
1>XMLDOMFromVCDlg.cpp(5706): error C2228: left of '.size' must have class/struct/union
1>          type is ''unknown-type''
1>XMLDOMFromVCDlg.cpp(5707): error C2065: 'vtrStyles3' : undeclared identifier
1>XMLDOMFromVCDlg.cpp(5707): error C2228: left of '.size' must have class/struct/union
1>          type is ''unknown-type''

所以这是怎么回事？提前致谢。

干杯

岱岳

Answer 1

有些事情您没有告诉我们。如果您定义 operator<，则以下程序(从您发布的代码中按部分复制粘贴)可以使用 Visual Studio 2008 进行编译。为你的 Styles结构(见下文)。

#include <set>
#include <string>
using namespace std;

struct Styles {
    wstring styleVal;
    wstring styleName;
};

int main ( int, char ** )
{
    set<Styles> vtrStyles1;
    set<Styles> vtrStyles2;
    set<Styles> vtrStyles3(vtrStyles1);
    vtrStyles3.insert(vtrStyles2.begin(), vtrStyles2.end());
    const size_t unCommon =
        vtrStyles1.size() + vtrStyles2.size() - vtrStyles3.size();
}

以下定义对我来说似乎没问题，但它可能不是您想要的。在 main() 之前插入这个.

bool operator< ( const Styles& lhs, const Styles& rhs )
{
    return (lhs.styleName < rhs.styleName);
}

如果你能编译这个程序，那么你的问题就出在别处。