Get calling this, if exists

[Mike Parker via Digitalmars-d-learn]

On Friday, 24 June 2016 at 03:04:25 UTC, Mike Parker wrote:
> On Friday, 24 June 2016 at 02:57:28 UTC, "Smoke" Adams wrote:
>> Is there a type of __THIS__ construct similar to __FILE__ and 
>> __LINE__?
>>
>> Something that returns the current this ptr if it exists, null 
>> otherwise.
>>
>> Log(string filename = __FILE__, Object obj = __THIS__)()
>> {
>>    // inspect obj and do stuff
>> }
>
> There is no 'this' pointer unless you are calling a member 
> function on an aggregate, so you can never have one that is 
> null.

Oh, perhaps I misunderstood your question. Do you meant this:

class Foo() {
    void bar() { Log(); }  // Pass reference to Foo instance
}

void doSomething() { Log(); } // Null reference

If so, the answer is no. And I don't see how that could work as a 
compile time parameter, given that the reference itself is a 
runtime value.