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digitalmars.D.bugs - Another template oddity?

reply David Medlock <amedlock nospam.org> writes:
template TVector(T,uint SZ)
{
   class Vector
   {
     T[SZ]     values;

     Vector  MyFunct(T f)
     {
       return new Vector();
     }
   }
}

class V3f : TVector!(float,3).Vector {}

void main( char[][] arg )
{
   V3f  v = new V3f();
   v = v.MyFunct(100.0f);
}

...
compiler gives me:

 "C:\dmd\bin\dmd.exe" -debug -c E:\proj\temp\bug2.d

cast(Vector )(v).MyFunct(100) of type Vector to V3f Should not this conversion be implicit?
Dec 09 2004
parent "Ben Hinkle" <bhinkle mathworks.com> writes:
"David Medlock" <amedlock nospam.org> wrote in message
news:cp9ng4$c9p$1 digitaldaemon.com...
 template TVector(T,uint SZ)
 {
    class Vector
    {
      T[SZ]     values;

      Vector  MyFunct(T f)
      {
        return new Vector();
      }
    }
 }

 class V3f : TVector!(float,3).Vector {}

 void main( char[][] arg )
 {
    V3f  v = new V3f();
    v = v.MyFunct(100.0f);
 }

 ...
 compiler gives me:

  > "C:\dmd\bin\dmd.exe" -debug -c E:\proj\temp\bug2.d
 E:\proj\temp\bug2.d(23): cannot implicitly convert expression
 cast(Vector )(v).MyFunct(100) of type Vector to V3f

 Should not this conversion be implicit?

The return type of MyFunct is Vector but it is assigning to a variable of type V3f, which is not allowed without a cast. It is like class Foo; class Bar : Foo; ... Bar x; ... x = new Foo; ... But this is allowed: Foo y; y = new Bar; By the way, your example can be shortened to: class Vector(T,uint SZ) { T[SZ] values; Vector MyFunct(T f) { return new Vector(); } } class V3f : Vector!(float,3) {} void main( char[][] arg ) { V3f v = new V3f(); v = v.MyFunct(100.0f); }
Dec 09 2004