从具有用户定义的String类的返回类型的函数返回std :: string时出错

Question

I have defined my own string class in "String.cpp" (class String ), in some function with return type String , i am trying to return std::string , but it throws error Error:

Cannot use std::string  to initialize PiaStd::String

Please help

String System::getHostName()
{
    // in between code
    std::string result;
    struct addrinfo* p;
    for(p = ppResult; p != 0; p=p->ai_next)
    {
        result += std::string(p->ai_canonname);
    }
    Freeaddrinfo(ppResult);
    return result;
}

Answer 1

The problem is that the compiler does not know how to make your string from std::string . You need to provide a way to do it by writing one of the following:

• Create a constructor of PiaStd::String that takes const std::string& as a parameter, or
• Create a custom conversion operator from std::string to PiaStd::String

You could also change getHostName() to make your custom string, or to return std::string .