Re: DIP66 - Multiple alias this

[via Digitalmars-d]

On Sunday, 12 October 2014 at 04:31:22 UTC, Walter Bright wrote:
On 10/11/2014 7:23 AM, IgorStepanov wrote:
class A
{
   int i;
   alias i this;
}
class B
{
   int i;
   alias i this;
}

class C
{
   A a;
   B b;
   alias a this;
   alias b this;
}

void foo(T)(T arg) if(is(T : int))
{
   ...
}

foo(C()); //Should it pass or not?

There's a rule with imports that if the same symbol is 
reachable via multiple paths through the imports, that it is 
not an ambiguity error. Here, the same type is reachable 
through multiple alias this paths, so by analogy it shouldn't 
be an error.

It's the same type, but different symbols; actual accesses would 
be ambiguous. `is(T : int)` shouldn't evaluate to true if `int a 
= T.init;` would fail.