Bug 7780 – Template mixin'd members do not properly overload

mixin template A( ) { template C( int n : 0 ) { int C = 0; } } mixin template B( ) { template C( int n : 1 ) { int C = 1; } } class Foo { mixin A!( ); mixin B!( ); } void main( ) { assert( Foo.C!0 == 0 ); } foo.d(19): Error: __overloadset isn't a template Or (without the wrapping class): foo.d(17): Error: template instance C!(0) ambiguous template declaration foo.B!().C(int n : 1) and foo.A!().C(int n : 0) The two versions of C here introduced could clearly coexist and be referred to as Foo.C!0 and Foo.C!1.

Also trivial methods hides mixin overloads: static struct A { // to generate a lot of repeating overloads // mixin will be good mixin template _bind(T, string S) { string bind(T var) { return S; } } mixin _bind!(short, "Short"); mixin _bind!(int, "Int"); string bind(long var) { return "Long"; } string bind(double var) { return "Double"; } } A a; short s; int i; long l; double d; string all = a.bind(s) ~ a.bind(i) ~ a.bind(l) ~ a.bind(d); assert(all == "ShortIntLongDouble"); // fail with "LongLongLongDouble" // mixin scopes is invisible for bind() overloading

(In reply to comment #1) > Also trivial methods hides mixin overloads: > [snip] Actually, that is quite clearly described under template mixins[1]: "If the name of a declaration in a mixin is the same as a declaration in the surrounding scope, the surrounding declaration overrides the mixin one" I agree it would be nice to have a way to not have them override, but I can absolutely see why one might want that rule. [1]: http://dlang.org/template-mixin.html

(In reply to comment #0) [snip] > > foo.d(19): Error: __overloadset isn't a template > > Or (without the wrapping class): > > foo.d(17): Error: template instance C!(0) ambiguous template declaration > foo.B!().C(int n : 1) and foo.A!().C(int n : 0) > > The two versions of C here introduced could clearly coexist and be referred to > as Foo.C!0 and Foo.C!1. https://github.com/D-Programming-Language/dmd/pull/1660

Commit pushed to master at https://github.com/D-Programming-Language/dmd https://github.com/D-Programming-Language/dmd/commit/f729d78d895a78a426de229c22cf3bc2174c142b fix Issue 7780 - Template mixin'd members do not properly overload