Expressing range constraints in CNF form

[H. S. Teoh via Digitalmars-d]

On Mon, Jun 12, 2017 at 10:35:59AM -0700, David Gileadi via Digitalmars-d wrote:
> On 6/11/17 1:32 PM, Sebastiaan Koppe wrote:
> 
> > What about using ddoc?
> > 
> > enum bool isInputRange(R) =
> >      is(typeof((ref R r) => r)) /// must be copyable
> >      && is(ReturnType!((R r) => r.empty) == bool) /// must support bool
> > empty
> >      && is(typeof(lvalueOf!R.front)) /// must support front
> >      && is(typeof(lvalueOf!R.popFront)) /// must support back
> 
> If there's going to be compiler magic, this seems like a sensible
> syntax--documenting constraints is a good idea anyway, particularly
> for those of us who aren't is-expression masters.

+1, I like this idea much better than any of the others proposed so far.
No need for additional syntax, reuse ddoc comment syntax for something
that, ostensibly, could be considered documentation.


T

-- 
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