On Sunday, 13 March 2016 at 02:33:49 UTC, Simen Kjaeraas wrote:
http://dpaste.dzfl.pl/7360ee90b344
Dammit, 3:30AM was apparently too late, and some bad code leaked
through. I managed to sidestep a problem by writing nonsense
code. The problem I get can be reduced to this:
struct S {
void foo(alias a)() {}
}
unittest {
S s;
s.foo!((int i) => 1); // Works
s.foo!(i => 1); // Fails
}
Result:
foo.d(8): Error: template instance foo!((i) => 1) cannot use
local '__lambda1' as parameter to non-global template foo(alias
a)()
Bah. It's in bugzilla as bug 5710[1] (with the most discussion),
3051, 3052, 11098, 12285, 12576 and 15564, and has a $150 bounty
on bountysource:
https://www.bountysource.com/issues/1375082-cannot-use-delegates-as-parameters-to-non-global-template
Maybe it's time I learnt how DMD is put together and earn $150...
Now, there's a way to work around that, by putting the lambda in
an intermediate type. Sadly, that runs afoul of bug 15794[2] for
the typed lambda, so I'm stumped for now.
[1]: https://issues.dlang.org/show_bug.cgi?id=5710
[2]: https://issues.dlang.org/show_bug.cgi?id=15794
