我试图建立一个名为Setop的类,该类提供集合操作,包括交集,union等。因此,我尝试使用C ++模板来实例化它。在Setop中,我使用QSet来存储集合的元素。我的代码如下所示:

设定档

    template <typename T> class SetOp {
    public:
        SetOp(std::vector<T> &_input);
void _union(SetOp<T> &_set2);
    QSet<T> _intersection(SetOp<T> &_set2);
    QSet<T> _diff(SetOp<T> &_set2);
    QSet<T> _diff(QSet<T> &_set1,QSet<T> &_set2);
    void outputElement();
    QSet<T> getSet(){return mySet;}
    std::vector<T> getVecFromQSet();
    private:
        QSet<T> mySet;
    };


setop.cpp:

template <typename T> SetOp<T>::SetOp(std::vector<T> &_input)
{
    for(int i = 0; i < (int)_input.size(); ++i)
        mySet.insert(_input[i]);
}


这是我尝试使用模板类的方法,我将boost :: tuples :: tuple传递给Setop:

    void MainWindow::setOp(std::vector<std::vector<boost::tuples::tuple<float,int,int,int> > > &_pointSet)
    {
       std::vector<std::vector<boost::tuples::tuple<float,int,int,int> > > merged;
       while(!_pointSet.empty()) {
           BOOST_AUTO(it,_pointSet.begin());
           BOOST_AUTO(itn,_pointSet.begin() + 1);
           SetOp<boost::tuples::tuple<float,int,int,int> > set1((*it)),set2((*itn));
           for(; itn != _pointSet.end();) {
               //           SetOp<boost::tuples::tuple<float,int,int,int> > temp = set1;
//           if(!temp._intersection(set2).isEmpty()) {
//               set1._union(set2);
//                itn = _pointSet.erase(itn);
//           }
//           else
//               ++itn;
           }
//       merged.push_back(set1.getVecFromQSet());
       }
    }


编译器生成以下错误:

c:\QtSDK\Desktop\Qt\4.8.1\mingw\include\QtCore\qhash.h:882: error:no matching function for call to 'qHash(const boost::tuples::tuple<float, int, int, int, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type>&)'
c:\QtSDK\Desktop\Qt\4.8.1\mingw\include\QtCore\qhash.h:225: error:no match for 'operator==' in 'key0 == ((QHashNode<boost::tuples::tuple<float, int, int, int, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type>, QHashDummyValue>*)this)->QHashNode<boost::tuples::tuple<float, int, int, int, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type>, QHashDummyValue>::key'


请问这些错误是什么意思,以及如何纠正它们?

最佳答案

From doc


  QSet类是提供基于散列表的集合的模板类。
  ...
  在内部,QSet被实现为QHash。


放在QHash内的任何值都应定义两者

operator==(const T& other)
uint qHash ( const T * key )

关于c++ - 在Qt中使用带有QSet和boost::tuples::tuple的模板时,没有匹配错误,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/13703663/

10-11 17:50