• d-bugmail puremagic.com (27/27) Dec 24 2022 https://issues.dlang.org/show_bug.cgi?id=23578

d-bugmail puremagic.com writes:

https://issues.dlang.org/show_bug.cgi?id=23578

          Issue ID: 23578
           Summary: Types are not matched to alias parameters in "is"
                    expression
           Product: D
           Version: D2
          Hardware: All
                OS: All
            Status: NEW
          Severity: normal
          Priority: P1
         Component: dmd
          Assignee: nobody puremagic.com
          Reporter: maxsamukha gmail.com

struct S(alias a)
{
}

static if (is(S!int == S!a, alias a))
    pragma(msg, a);
else
    static assert(false);

Output:
onlineapp.d(4): Error: static assert:  `false` is false


I don't know whether it's a bug or enhancement. The spec is unclear on this. It
is reasonable to expect 'alias' parameters in 'is' expressions to be treated
consistently with template parameters.

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