Correct way to define C++ namespace methods in .cpp file

Question

Probably a duplicate, but not an easy one to search for...

Given a header like:

namespace ns1
{
 class MyClass
 {
  void method();
 };
}

Answer 1

5 years later and i thought I'd mention this, which both looks nice and is not evil

using ns1::MyClass;

void MyClass::method()
{
  // ...
}