[Issue 2328] New: setTypeInfo in gc.d backwards.

[dsimcha]

== Quote from Sean Kelly (sean at invisibleduck.org)'s article
> d-bugmail at puremagic.com wrote:
> > http://d.puremagic.com/issues/show_bug.cgi?id=2328
> >
> >            Summary: setTypeInfo in gc.d backwards.
> >            Product: D
> >            Version: 2.018
> >           Platform: All
> >         OS/Version: All
> >             Status: NEW
> >           Severity: major
> >           Priority: P2
> >          Component: Phobos
> >         AssignedTo: bugzilla at digitalmars.com
> >         ReportedBy: dsimcha at yahoo.com
> >
> >
> > According to Phobos object docs:
> >
> > uint flags();
> >     Get flags for type: 1 means GC should scan for pointers
> >
> > This is implemented correctly.
> >
> > import std.stdio;
> >
> > void main() {
> >     writefln(typeid(uint).flags & 1);  //0
> >     writefln(typeid(uint*).flags & 1); //1
> >     writefln(typeid(void*).flags & 1); //1
> >     writefln(typeid(float).flags & 1); //0
> > }
> >
> > However, source code to setTypeInfo:
> >
> > void setTypeInfo(TypeInfo ti, void* p)
> > {
> >     if (ti.flags() & 1)
> >         hasNoPointers(p);
> >     else
> >         hasPointers(p);
> > }
> >
> > The if statement in this code is clearly backwards.
> I'm fairly certain that the doc comment is simply wrong.  Last time I
> checked, the flag was 1 for "has no pointers" as per the implementation.
>   I'd actually prefer it to work as the comment suggests, however.

Nope, I actually tested the implementation.  I didn't just assume the doc comment
was right.  Furthermore, I tried to write code based on the expected behavior of
Phobos's setTypeInfo() and it was clearly broken.  Lying to setTypeInfo() about
the type fixed it.  Note that I don't know if this bug exists in Tango or
Phobos/D1, only that it does exist in Phobos/D2.