Bug 4174 – Template interface functions not allowed, making operator overloads difficult

Sorry, enter key added the issue when I was typing the summary. Operator overloads require template functions, yet this doesn't work: interface I { I addAssign(I other); I opOpAssign(string op)(I other) if (op == "+=") { return this.addAssign(other); } } void foo(I i) { i += i; } error message: testinterface.d(4): Error: function testinterface.I.opOpAssign!("+=").opOpAssign template member functions are not allowed in interface I testinterface.d(12): Error: template instance testinterface.I.opOpAssign!("+=") error instantiating How shall I implement operators for interfaces?

That should be op == "+". With that change I am getting the same error message. Assigning to Walter to expedite review.

Yes, I think back in May, you needed "+=".

Any news on this? This is still very much a blocker for many designs.

*** Issue 7816 has been marked as a duplicate of this issue. ***

Commits pushed to master at https://github.com/D-Programming-Language/dmd https://github.com/D-Programming-Language/dmd/commit/bb9200a4f80c912a4b9e4c4649307d86edb0624c Issue 4174 - Template interface functions not allowed, making operator overloads difficult The lifting restriction banning final and static members in interfaces should also apply to template functions. https://github.com/D-Programming-Language/dmd/commit/f1f09dd8ef3710e631d387268a5cf03507ccf99b Merge pull request #131 from yebblies/issue4174 Issue 4174 - Template interface functions not allowed, making operator overloads difficult