My template tuple code does not compile
porton at narod.ru
Tue Feb 26 22:56:37 UTC 2019
On Tuesday, 26 February 2019 at 22:51:15 UTC, Q. Schroll wrote:
> On Tuesday, 26 February 2019 at 21:43:31 UTC, Victor Porton
>> Compilation of unittest at the bottom of this file fails with
>> an error. What is my error?
> You have the line
> ProviderParams("S", ((int, "x"), (float, "y")));
> Why do you even expect it to compile?
> First, ProviderParams is a mixin template, so you'd need to
> instantiate it with the ! operator. Then, the expressions (int,
> "x") and so on do not make sense in D. You could have
> compile-time tuples (using AliasSeq from std.meta) containing
> types and other compile-time known stuff, but it wouldn't help
> You'd use the mixin template like this:
> mixin ProviderParams!("S", int, "x", float, "y");
> ^-- necessary ^-- necessary
> Grouping arguments could be done, but from my experience, it
> does not buy you anything; rather it makes it worse. Better
> just deal with heterogeneous stuff just like std.typecons.Tuple
> You should definitely comment your code. Explain what you
> intend to do. It helps people helping you.
After fixing the error you pointed me, it does not work too:
mixin ProviderParams!("S", ((int, "x"), (float, "y")));
Also: Can I nevertheless group arguments?
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