On Wednesday, 27 September 2017 at 16:35:54 UTC, DreadKyller
wrote:
My question is about overloading, several operators can be
overloaded in D, one of the ones that can't apparently is the
address of operator (&object). My question is have I simply
missed it or does it actually not exist, and if it's not
overloadable, is there any reason why this was decided? Because
there's been numerous times that it'd be useful to me, just
recently with how much I use the operator because of OpenGL I
decided to ask.
My answer is that & is a defined operation on all addressable
memory. Unlike other operators which don't exist until you
"overload" them.
For example, if you store your Matrix in a custom container it
could try to store pointer rather than the struct itself, if & is
overloaded the generic implementation would be broken because it
would no longer be a pointer to Matrix but to the inner element.
Whereas generic code which utilizes addition or append can assume
the type appropriately defined the behavior to semantically match
the desired use, generic code would be broken if the type changed
& to do something different from what the language defines it to
do.
