On Sunday, 11 June 2017 at 00:28:58 UTC, Andrei Alexandrescu
wrote:
https://github.com/dlang/phobos/pull/5461
There's many good advantages to this. The immediate one is the
constraint is better structured and easier to understand. Then,
the compiler can print the exact clause that failed, which
improves the precision and quality of the error message.
Great!
// Also possible (no change to the language)
enum bool isInputRange(R) =
is(typeof((ref R r) => r)) && msg("must be copyable")
&& is(ReturnType!((R r) => r.empty) == bool) && msg("must
support bool empty")
&& is(typeof(lvalueOf!R.front)) && msg("must support front")
&& is(typeof(lvalueOf!R.popFront)) && msg("must support
back");
I'm not getting how this works.
