Re: [boost] [static_if] Is there interest in a `static if` emulation library?

Subject: Re: [boost] [static_if] Is there interest in a `static if` emulation library?
From: Lorenzo Caminiti (lorcaminiti_at_[hidden])
Date: 2014-09-01 21:06:23

On Mon, Sep 1, 2014 at 11:26 AM, Matt Calabrese <rivorus_at_[hidden]> wrote:
> On Mon, Sep 1, 2014 at 8:00 AM, Robert Ramey <ramey_at_[hidden]> wrote:
>
>> The compile-times argument doesn't impress me much though.  Using
>> a much more complex syntax or new library to shave a tiny bit of
>
> ...
>
> Even if your condition is known through a compile-time
> constant bool, If you don't add a level of indirection to prevent both from
> being instantiated, either manually or by way of a higher-level facility
> like a static if, your compile time for that translation unit can possibly
> double, or worse.

Yes, the point of static if wouldn't necessarily be performance even
if compile-time performance could be improved by it, as Matt already
pointed out (similar points are made in the various static if
N-papers).

In fact, in my original example the static if is used for correctness
and not performance (so to check the assertion when T provides the
appropriate operations for the check to actually compile).

--Lorenzo