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 | Posted by Bolpat |  Permalink Reply |
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Bolpat 
| https://issues.dlang.org/show_bug.cgi?id=24039
--- Comment #2 from Bolpat <qs.il.paperinik@gmail.com> ---
(In reply to Dennis from comment #1)
> If I understand correctly, you want the compiler to rewrite `1.opBinary!"+"(2)` to `1 + 2` for meta-programming. Can you give an example where you want to use this, instead of just the + operator?
I don’t want to write `1.opBinary!"+"(2)` directly, there’s clearly not much use for this, but I definitely want to be able to use the `hasMember` trait or something like that. It makes it easier to forward operations as well (currently, you need a mixin). With `opBinary` (and `opUnary`), it’s rather unspecific, but think of `opCall`, `opIndex`, `opEquals` or `opCmp`.
Just imagine how much clearer template code becomes when the question “Does
this support comparison?” is exactly identical to “Is there a member `opCmp`?”.
Same for `opEquals`. Same for `opCall`.
It’s mostly about consistency and lowering the mental burden. Ideally, built-in
types are as un-special as possible. If built-in types behaved like
user-defined types, there should be those member functions.
I stumbled into this when attempting to write a trait to find out if a type has partial comparison, i.e. has values that are neither ≤ nor ≥. Ideally, you check the result of `opCmp`, but no, there’s so many built-in types that I’m never really sure I handled all.
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