All the elements of the standard C++ library are declared within what is called a namespace, the
namespace with the name std. So in order to access its functionality we declare with this expression that
we will be using these entities. This line is very frequent in C++ programs that use the standard library,
and in fact it will be included in most of the source codes
namespace with the name std. So in order to access its functionality we declare with this expression that
we will be using these entities. This line is very frequent in C++ programs that use the standard library,
and in fact it will be included in most of the source codes