Question

我在Windows 10上使用VS2008。我有这个功能的问题，希望你能帮助我

void CPythonNetworkStream::AppearShopSign(DWORD dwVID, std::string stSign) {
    if (stSign.empty())
        for (auto it = m_mapShopSign.begin(); it != m_mapShopSign.end(); ++it)
            if (dwVID == it->first)
                stSign = it->second;

    // LogBoxf("AppearShopSign: %u-%s", dwVID, stSign.c_str());
    PyCallClassMemberFunc(m_apoPhaseWnd[PHASE_WINDOW_GAME], "BINARY_PrivateShop_Appear", Py_BuildValue("(is)", dwVID, stSign.c_str()));
}

错误消息

error C4430: missing type specifier - int assumed. Note: C++ does not support default-int   
error C2440: 'initializing' : cannot convert from 'std::_Tree<_Traits>::iterator' to 'int' 
error C2678: binary '!=' : no operator found which takes a left-hand operand of type 'int' (or there is no acceptable conversion)
error C2227: left of '->first' must point to class/struct/union/generic type

Answer 1

自c ++ 11标准以来支持auto关键字，而visual-studio 2008无法使用该标准。

要修复它，请使用显式类型：

for (std::map<DWORD,std::string>::iterator it = m_mapShopSign.begin(); 
  // ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
     it != m_mapShopSign.end(); 
     ++it)

Answer 2

如上所述，auto是在{+ 3}}的C ++ 11中引入的。在C ++ 11之前，它用于声明具有自动存储持续时间的局部变量。

使用`auto`产生错误C4430：缺少类型说明符 - 假设为int。注意：C ++不支持default-int

2 个答案: