• d-bugmail puremagic.com (70/70) Jul 27 2022 https://issues.dlang.org/show_bug.cgi?id=23272

d-bugmail puremagic.com writes:

https://issues.dlang.org/show_bug.cgi?id=23272

          Issue ID: 23272
           Summary: [REG2.099] CTFE error of typeid comparison ==
           Product: D
           Version: D2
          Hardware: All
                OS: All
            Status: NEW
          Severity: regression
          Priority: P1
         Component: dmd
          Assignee: nobody puremagic.com
          Reporter: johanengelen weka.io

Unfortunately a rather large testcase:

Testcase:
```
import std.string;
import std.conv;
import std.traits;
import std.typetuple;

struct SumType(Ts...) {

    mixin(() {
        auto s = "enum Cases : ubyte {";
        foreach(i, _; Ts) {
            s ~= "c" ~ text(i) ~ " = " ~ text(i) ~ ", ";
        }
        return s ~= "unset}\n";
    }());

    Cases which = Cases.unset;
    union {
        Ts cases;
    }

    auto ref opAssign(U)(auto ref U val) {
        enum idx = staticIndexOf!(Unqual!U, Ts);
        cases[idx] = val;
        which = cast(Cases)idx;
        return this;
    }
}

auto caseOfTemplated(alias func, T)(auto ref T s) {
    final switch (s.which) foreach(i, CASE; EnumMembers!(T.Cases)) {
        case CASE:
            static if (CASE == T.Cases.unset) {
                assert (false, "not set");
            } else {
                return func(s.cases[i]);
            }
    }
    assert (false);
}


void foo() {
    bool validate() {
        SumType!(string, int) s;
        s = "hello";

        assert (caseOfTemplated!(a => typeid(a))(s) == typeid(string));
        return true;
    }
    static assert(validate());
}
```

Compilation fails with since dlang2.099 (works for older frontend versions):
/opt/compiler-explorer/ldc1.29.0/ldc2-1.29.0-linux-x86_64/bin/../import/object.d(329):
Error: cannot convert `&object.TypeInfo` to `Object*` at compile time
/opt/compiler-explorer/ldc1.29.0/ldc2-1.29.0-linux-x86_64/bin/../import/object.d(329):
       called from here: `opEquals(*& lhs, *& rhs)`
<source>(47):        called from here: `opEquals(caseOfTemplated(s),
typeid(string))`
<source>(50):        called from here: `validate()`
<source>(50):        while evaluating: `static assert(validate())`

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