Use enum base type?

[Janissary]

Is it possible to evaluate an enum's base type? Ideally something 
like:


enum somestrs : string { ... }
enum d = 0.0;
template EnumBaseType(E) if (is(E==enum)) { ... }
unittest {
   static assert( is(EnumBaseType!somestrs == string) );
   static assert( is(EnumBaseType!d : float) );
   static assert(!is(EnumBaseType!d == float) );
}

A template like this would make at least my life easier.

Re: Use enum base type?

[Simen Kjaeraas]

On 2013-04-17, 19:15, Janissary wrote:


Is it possible to evaluate an enum's base type? Ideally something like:

enum somestrs : string { ... }
enum d = 0.0;
template EnumBaseType(E) if (is(E==enum)) { ... }
unittest {
static assert( is(EnumBaseType!somestrs == string) );
static assert( is(EnumBaseType!d : float) );
static assert(!is(EnumBaseType!d == float) );
}

A template like this would make at least my life easier.


Whenever you want to do weird stuff with types, std.traits[1] should
be your #1 stop. And quite correctly, std.traits.OriginalType[2] does
what you want:

  enum E : int { a }
  typedef E F;
  typedef const F G;
  static assert(is(OriginalType!G == const int));

[1]: http://dlang.org/phobos/std_traits
[2]: http://dlang.org/phobos/std_traits#.OriginalType
--
Simen

Re: Use enum base type?

[Janissary]

On Wednesday, 17 April 2013 at 18:56:43 UTC, Simen Kjaeraas wrote:

On 2013-04-17, 19:15, Janissary wrote:

Is it possible to evaluate an enum's base type? Ideally 
something like:


enum somestrs : string { ... }
enum d = 0.0;
template EnumBaseType(E) if (is(E==enum)) { ... }
unittest {
   static assert( is(EnumBaseType!somestrs == string) );
   static assert( is(EnumBaseType!d : float) );
   static assert(!is(EnumBaseType!d == float) );
}

A template like this would make at least my life easier.


Whenever you want to do weird stuff with types, std.traits[1] 
should
be your #1 stop. And quite correctly, 
std.traits.OriginalType[2] does

what you want:

  enum E : int { a }
  typedef E F;
  typedef const F G;
  static assert(is(OriginalType!G == const int));

[1]: http://dlang.org/phobos/std_traits
[2]: http://dlang.org/phobos/std_traits#.OriginalType


Thanks, that's just what I needed.