user defined namespace in c++ code example

Example 1: c++ custom namespace

//using namespaces
using namespace std;

//creating namespaces
namespace custom{
  class example{
    public:
    	static int method(){
          return 0;
        }
  };
};

//using custom namespaces
using namespace custom;

Example 2: access the namespace members using namespace member function

namespace Parent
{
    inline namespace new_ns
    {
         template <typename T>
         struct C
         {
             T member;
         };
    }
     template<>
     class C<int> {};
}