Issue 12568 - std.functional.memoize does not work with constant arrays

[ghost]

https://issues.dlang.org/show_bug.cgi?id=12568

This smells like a type-inference compiler bug, or a type-inference hash lookup issue. I'll ping @9rnsr to be sure.

[monarchdodra]

If you write it as auto t = tuple!(typeof(args))(args) (or Tuple!(...) too), you get the same result, but you (should) avoid a potential "converting" constructor when the types miss-match.

Either that, or change the [Tuple!(typeof(args))] above to [typeof(tuple(args))]. Nah...

BTW: typeof(args) is literally the ParameterTypeTuple!fun used in the function signature. It might be beter to just alias Args = ParameterTypeTuple!fun in the template body, and then just use that:

template memoize(alias fun, uint maxSize = uint.max)
{
    alias Args = ParameterTypeTuple!fun;
    ReturnType!fun memoize(Args args)
    {
        import std.typecons : Tuple, tuple;
        static ReturnType!fun[Tuple!Args] memo;
        auto t = Tuple!Args(args);
        ...

[ghost]

Nice. I think I'll use that.

[ghost]

Updated.

[monarchdodra]

BTW, (I can't remember if I said it yet), but thanks for fixing all these issues.

Also, my comments are (usually) just nitpicks. If you care to take them into account, that's great. But your pulls are usually good as is, and I wouldn't want to get in the way of things actually getting fixed. Do say "I don't feel like it" when you can't be bothered, and I'll pull as is.

[ghost]

BTW, (I can't remember if I said it yet), but thanks for fixing all these issues.

Thanks!

Also, my comments are (usually) just nitpicks

Not really, I appreciate proper reviews that can help us push better code to the stdlib. I have no problems amending something, and I'm in no rush. Thanks for all the help so far!

[ghost]

Failure is likely random.

[yebblies]

You can force the tester to re-run by clicking the 'deprecate' link on the result page

[ghost]

You can force the tester to re-run by clicking the 'deprecate' link on the result page

Hmm, that's interesting, but I can't find it (I guess because you clicked it?).

[yebblies]

Yeah, it goes next to 'Deleted' and you can see it on the pages for the other runs.