• dnspies (8/8) Apr 05 2014 Is there a way to do a checked cast from a base type to an
• Chris Nicholson-Sauls (13/21) Apr 05 2014 enum E : dchar {

"dnspies" <dspies ualberta.ca> writes:

Is there a way to do a checked cast from a base type to an 
enum-type (so that an exception is thrown if it fails)?

ie something like

enum x : dchar { A : 'a', B : 'b', C : 'c' };

x get_x() {
  dchar r = get_char();
  return cast(x)r; //Throw exception if this cast fails
}

"Chris Nicholson-Sauls" <ibisbasenji gmail.com> writes:

On Sunday, 6 April 2014 at 02:21:35 UTC, dnspies wrote:
 Is there a way to do a checked cast from a base type to an 
 enum-type (so that an exception is thrown if it fails)?

 ie something like

 enum x : dchar { A : 'a', B : 'b', C : 'c' };

 x get_x() {
  dchar r = get_char();
  return cast(x)r; //Throw exception if this cast fails
 }


enum E : dchar {
     A = 'a',
     B = 'b',
     C = 'c'
}

void main () {
     import std.conv;
     dchar c = 'd';
     E e = to!E( c );
}


std.conv.ConvException /home/grant/.dvm/compilers/dmd-2.064.2/bin/../src/phob
s/std/conv.d(1854): 
Value (d) does not match any member value of enum 'E'