c++ - catch block gives me no match for operator error

Question

I am trying to catch the exception like below -

try {

} catch (const std::exception& ex) {
    cout << "An exception occurred when executing query. " << ex << endl;
}

But everytime I am getting this error -

no match for operator<< in std::operator<< <std::char_traits<char> >((* & std::cout), ((const char*)"An exception occurred when executing query. ")) << ex

Any idea what wrong I am doing here?

Answer 1

用这个

cout << "An exception occurred when executing query. " << ex.what() << endl;

运算符在类<<中没有重载。exception

Answer 2

编译器（试图）告诉你 anoperator<<(std::ostream&, std::exception const&)没有声明。

Answer 3

<<匹配的运算符没有重载std::exception。改为使用ex.what()。 what()返回一个char*明白<<的。参考： http ://www.cplusplus.com/reference/exception/exception/what/