opApply outside of struct/class scope

[Era Scarecrow via Digitalmars-d-learn]

On Sunday, 10 August 2014 at 18:58:50 UTC, Jonathan M Davis wrote:
> No overloaded operators in D can be put outside of a struct or 
> class. They have to be member functions.

  If I remember right, opApply was somewhat broken and only worked 
correctly in a few cases. But that was 18 months ago, a lot could 
have happened...