Question

Is there a point of doing somthing like this:

namespace status{
  enum status{
    ok,
    error
  };
}

and use it like that status::ok

Or should i do this:

enum status{
  status_ok,
  status_error
};

and use it like this status_ok?

Update:
With C++11 you now should do this:

enum class status {
    ok,
    error
};

and use like this: status::ok

Answer 1

I personally don’t like the second variation because the status_ part seems redundant to me. The former version avoids that problem, but having a type status::status looks strange too. Furthermore, a namespace is open to modification, so in case somebody did something like

namespace status {
  void error( const char *msg );
}

You would get a compiler error since the function error clashes with your enum value.

I prefer to use a third variation:

struct MouseButton {
  enum Value {
    Left, Middle, Right
  };
};

This lets me write functions like

void handleMouseButton( MouseButton::Value b ) {
  switch ( b ) {
    case MouseButton::Left:   // ...
    case MouseButton::Middle: // ...
    case MouseButton::Right:  // ...
  }
}