Re: (Forward) declarations of enums

From: (Alberto Ganesh Barbati)
Sat, 15 Dec 2007 15:11:28 GMT
Francis Glassborow ha scritto:

Lance Diduck wrote:

3) should be able to have a user defined ctors, just like any other
user defined type

I strongly disagree. There is no need for that and would make
enumerations a more complex entity than they are meant to be.

I can already overload operators for them, and C++TPL give examples of
a operator++ for enums. I routinely overload operator<<(std::ostream
&,Enum) form mine for the obvious reasons.
I dont understand how giving enums ctors complicates anything. It
would be very similar to the semantics of union ctors and dtors.

Sorry but I can see very little (if any) use for ctors for (strong)
enums. The only feature I would like to add to enums is the possibility
of a user defined operator=.

You can easily emulate that (and constructors too), by wrapping the enum
inside a struct, for example:

struct E
  enum EDetail : int
     /* enumerators */

  // constructors
  constexpr E() : e(default-value-here) {}
  explicit constexpr E(int x) : e(x) {}

  // conversion operators
  explicit constexpr operator int() { return e; }

  // other stuff
  E& operator=(whatever);

  EDetail e;



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