Bug 1225 – Super Class method hides the global template from mixin

import std.stdio; template dup(T){ T dup(){ auto c=new T; foreach(i,x;T.tupleof) { c.tupleof[i]=x; writefln(`tupleof `,i); } return c; } } class baseclass { mixin dup!(baseclass); void method(){printf("a.method\n");} } class deriveclass:baseclass { mixin dup!(deriveclass); int j; void method(){printf("b.method\n");} } void main() { deriveclass mybinstance = new deriveclass; mybinstance.dup; } compiler complains: testclass.d(21): mixin dup isn't a template

This illustrate the bug a little more clearly, and also fix some issues of the original code. import std.stdio; template dup(T){ T dup(){ auto c=new T; foreach(i,x;this.tupleof) { c.tupleof[i]=x; writefln(`tupleof `,x); } return c; } } class baseclass { // mixin dup!(baseclass); // comment this , the dup won't be hidden anymore in the derive class void method(){printf("a.method\n");} } class deriveclass:baseclass { mixin dup!(deriveclass); int j; float i; void method(){printf("b.method\n");} this() { i=34; j=10; } } void main() { deriveclass mybinstance = new deriveclass; mybinstance.dup(); }

*** Bug 1527 has been marked as a duplicate of this bug. ***

I don't think that this is actually a bug. You can specify that you want the outer scope symbol by using in this line in the child class (with the mixin in the parent class uncommented): mixin .dup!(deriveclass); But then you will end up with an error stating you forgot to use the override keyword: Error: cannot implicitly override base class method test.baseclass.dup!(baseclass).dup with test.deriveclass.dup!(deriveclass).dup; add override attribute This is the correct, documented behavior. Closing as invalid. Please reopen if I am missing something.