April 08, 2019
https://issues.dlang.org/show_bug.cgi?id=19793

          Issue ID: 19793
           Summary: no postblit is called if cast is used for structs
           Product: D
           Version: D2
          Hardware: All
                OS: All
            Status: NEW
          Severity: critical
          Priority: P1
         Component: dmd
          Assignee: nobody@puremagic.com
          Reporter: ilyayaroshenko@gmail.com

struct S(T)
{
    size_t* counter;

    this(this)
    {
        if (counter)
            ++counter[0];
    }

    ~this()
    {
        if (counter)
            --counter[0];
    }

    static S create()
    {
        return S(new size_t(1));
    }
}

auto constOf(S!int a)
{
    return cast(S!(const int)) a;
}

void main()
{
        auto s = S!int.create;
    assert(s.counter[0] == 1); // pass
    auto a = constOf(s);
    assert(s.counter[0] == 2); // fails
}

--