On Thursday, 30 June 2016 at 11:06:56 UTC, Steven Schveighoffer
wrote:
On 6/29/16 11:40 AM, Wyatt wrote:
I might be stepping on a land mine by bringing it up, but
isn't this
sort of thing what contracts are for?
No landmines here, but no, that isn't what contracts are for.
Perhaps you mean constraints?
Sure. IME, contracts are generally written as a series of
constraints anyway.
A constraint will prevent compilation vs. allowing compilation
but emitting a failure at runtime. I agree this is a better
mechanism, or just plain allow the compiler to make a proper
error when you call gun.
Isn't doing it at compile time as simple as using e.g. static
assert(hasMember(T, "gun"))? I do feel like I've been in
situations before where this kind of thing was better as a
recoverable runtime exception, but I can't remember where.
The more I think about this, though, the less the proposal makes
sense for the problem. Like, I get that it might be a tiny bit
annoying, but I see a lot more potential for human error; pulling
a "goto FAIL" and running code that shouldn't be or such.
-Wyatt
