disable all member function calls for rvalues?

[dsimcha]

== Quote from Andrei Alexandrescu (SeeWebsiteForEmail at erdani.org)'s article
> There is a wart in D I'd like to eliminate. Unfortunately, that would
> also eliminate some valid uses.

This is the problem, with this feature and with a lot of other "safety" features
that have been considered.  Having lots of static checking, etc. is good if and
only if it doesn't get in the way too much when the programmer **does** know what
he/she is doing.  Yes, this limitation would prevent some bugs, but it would get
in the way very frequently as well and be an extremely annoying piece of syntactic
salt.  Given the choice I'd rather have to debug a few more bugs in corner cases
than have the language reject lots of valid cases.

Of course, there's room for intermediate solutions:

1.  Allow member function calls iff the function is const.  For example, the
following would still work:

struct A {
    string toString() const {
         return "A";
    }
}

struct B {
    A getA() @property {
        return A.init;
    }
}

B b;
string s = b.getA().toString();

2.  Special case opAssign, since this clearly makes no sense for rvalues.

3.  If consistency is the main concern, make other ref rvalue binding more
permissive instead.