User-defined "opIs"

[Marco Leise via Digitalmars-d]

Am Sun, 28 Sep 2014 10:44:47 +0000
schrieb "Marc Schütz" <schuetzm at gmx.net>:

> On Saturday, 27 September 2014 at 11:38:51 UTC, Marco Leise wrote:
> >   A byte for byte comparison of both operands is performed.
> >   For reference types this is the reference itself.
> 
> Maybe allow this only for types that somehow implicitly convert 
> to each other, i.e. via alias this?

That sounds like a messy rule set on top of the original when
alias this does not represent all of the type. You have a
size_t and a struct with a pointer that aliases itself to some
size_t that can be retrieved through that pointer.
The alias this will make it implicitly convert to size_t and
the byte for byte comparison will happily compare two equally
sized varibles (size_t and pointer).
So how narrow would the rule have to be defined before it
reads:

  If you compare with a struct that consists only of one member
  that the struct aliases itself with, a variable of the type
  of that member will be compared byte for byte with the
  struct.

-- 
Marco