• via Digitalmars-d-bugs (64/64) May 10 2016 https://issues.dlang.org/show_bug.cgi?id=16012

via Digitalmars-d-bugs <digitalmars-d-bugs puremagic.com> writes:

https://issues.dlang.org/show_bug.cgi?id=16012

          Issue ID: 16012
           Summary: [REG2.070] forward reference with alias this
           Product: D
           Version: D2
          Hardware: x86_64
                OS: Linux
            Status: NEW
          Keywords: rejects-valid
          Severity: regression
          Priority: P1
         Component: dmd
          Assignee: nobody puremagic.com
          Reporter: ag0aep6g gmail.com

This is a reduction of issue 16011. Fixing this possibly also fixes that one,
but since this fails with different versions of dmd, there may be something
else going on in addition.

----
void emplace(S* chunk) { *chunk = S.init; }

struct RefCounted()
{
    struct RefCountedStore
    {
        struct Impl { S _payload; }

        Impl* _store;

        void initialize()
        {
            _store = new Impl; /* line 13 */
            emplace(&_store._payload); /* line 14 */
        }
    }

    RefCountedStore _refCounted;

    void opAssign(typeof(this) rhs) {}
    void opAssign(S rhs) {}

    ref S refCountedPayload()
    {
        if (_refCounted._store is null) _refCounted.initialize();
        return _refCounted._store._payload;
    }

    alias refCountedPayload this;
}


struct S
{
    int x;
    RefCounted!() s;
}

void main()
{
    S s;

    s.x = 1;
    s.s.x = 2;
    s.s.s.x = 3;

    assert(s.x == 1);
    assert(s.s.x == 2);
    assert(s.s.s.x == 3);
}

----

2.069.2: Compiles and passes asserts.
2.070.2, 2.071.0: "test.d(13): Error: struct
test.RefCounted!().RefCounted.RefCountedStore.Impl no size yet for forward
reference"
git master (bc74f4a): "test.d(14): Error: forward reference to
(*this._store)._payload"

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