Question

Why in the below code without including “string” header I can declare string variable.
But compiler complains only for cout, when I try to print the string.

What information “string” header consists of ?

  #include <iostream>
//#include "string"

int main () 
{
    std::string str="SomeWorld";

    std::cout<<str<<std::endl;

  return 0;
}

Answer 1

Because the header defining std::basic_string is most likely (indirectly) included by <iostream> (std::string is a typedef based on std::basic_string<char>). The overload for operator<< for std::cout however is only defined in <string>.