On Wednesday, 15 March 2017 at 20:36:27 UTC, H. S. Teoh wrote:
But if the class declares this()
and the (single) mixin template also declares this(), then the
mixin
template's version is ignored and the class-declared this() is
run upon
construction.
That's normal mixin template behavior: if the name of a mixed in
object already exists in the instantiation scope, the existing
one is preferred. This allows you to "override" mixin functions
and is quite useful. You can also bring in the others via alias.
See my tip here for a related factoid:
http://arsdnet.net/this-week-in-d/2016-feb-07.html
That's what I *thought* was going on with the destructor too...
but I confirmed both do in fact exist and seem to be merged by
the compiler. I knew it did that with static dtors, but the spec
says "a class can have only one destructor and it is always
virtual" so idk what's going on. Bug, perhaps, but I now am
inclined to believe it is a hidden feature.
Important note though: such behavior is already possible. Struct
dtors of members are called when the class dtor runs too...
However, if there are two mixin templates both declaring
this(), the compiler dies with an ICE. :-D
eek.
