小编Tr0*_*03P的帖子

在作用域中创建临时对象时,编译器不会看到构造函数提供的参数并给出编译错误.

如下例所示:

#include <sstream>
#include <iostream>

class csventry
{
public:
        csventry(std::ostream& ostream) :
                _ostream(ostream)
                {}

        ~csventry() 
                { _ostream << std::endl; }

        csventry& operator << (const std::string& value) {
                _ostream << ", ";
                _ostream << value;
                return *this;
        }

private:
        std::ostream& _ostream;
};

int main () 
{
        std::ostringstream log;

        { csventry(log) << "User Log-on:"; }
        { csventry(log); }
        { csventry(log) << "Summary:"; }

        std::cout<<log.str()<<std::endl;
}

我收到这个错误.

main.cpp: In function ‘int main()’:
main.cpp:29:16: error: no matching function for call to ‘csventry::csventry()’
  { …