mixin template and overloading

[Luc Bourhis via Digitalmars-d]

Consider:

~ % dmd -v|head -n 1
DMD64 D Compiler v2.066-devel

~% cat mixin_template_pb.d
mixin template Foo(T) {
  void bar() {}
}

struct FooBar {
  mixin Foo!int;
  void bar(ulong d)() {}
}

void check() {
  FooBar o;
  o.bar();
}
~% dmd -c mixin_template_pb.d
mixin_template_pb.d(12): Error: template 
mixin_template_pb.FooBar.bar cannot deduce function from argument 
types !()(), candidates are:
mixin_template_pb.d(7):mixin_template_pb.FooBar.bar(ulong 
d)()


It looks like the compiler does not see the mixed-in "bar". If I 
comment out the definition of "bar" in "FooBar", it compiles 
fine. Is this to be considered a bug?

Re: mixin template and overloading

[anonymous via Digitalmars-d]

On Tuesday, 20 January 2015 at 11:30:39 UTC, Luc Bourhis wrote:

Consider:

~ % dmd -v|head -n 1
DMD64 D Compiler v2.066-devel

~% cat mixin_template_pb.d
mixin template Foo(T) {
  void bar() {}
}

struct FooBar {
  mixin Foo!int;
  void bar(ulong d)() {}
}

void check() {
  FooBar o;
  o.bar();
}
~% dmd -c mixin_template_pb.d
mixin_template_pb.d(12): Error: template 
mixin_template_pb.FooBar.bar cannot deduce function from 
argument types !()(), candidates are:
mixin_template_pb.d(7):
mixin_template_pb.FooBar.bar(ulong d)()


It looks like the compiler does not see the mixed-in "bar". If 
I comment out the definition of "bar" in "FooBar", it compiles 
fine. Is this to be considered a bug?


No, it's working as intended: "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" -- 
http://dlang.org/template-mixin.html


You can use `alias` to bring the two together:

struct FooBar {
  mixin Foo!int f;
  alias bar = f.bar;
  void bar(ulong d)() {}
}