Get calling this, if exists

[Steven Schveighoffer via Digitalmars-d-learn]

On 6/24/16 11:15 AM, Smoke Adams wrote:
> On Friday, 24 June 2016 at 03:16:58 UTC, Meta wrote:
>> On Friday, 24 June 2016 at 03:10:51 UTC, Mike Parker wrote:
>>> 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.
>>
>> It actually is possible. You just have to be explicit.
>>
>> void log(alias self)(string s)
>> {
>>     pragma(msg, self.stringof);
>> }
>>
>> struct Test
>> {
>>     void test(string s)
>>     {
>>         log!this(s);
>>     }
>> }
>>
>> void main()
>> {
>>     Test t;
>>     t.test("asdf");
>> }
>
> I don't want to be explicit! One can be explicit with __FILE__ too but
> one doesn't have to be.

__FILE__ is a constant, so is __LINE__. __THIS__ would not be, so this 
is somewhat different.

With UFCS, you can get close:

void log(T)(T obj, string s)
{
    ...
}

struct Test
{
    void test(string s)
    {
       this.log(s);
    }
}

But I believe you have to call with explict 'this'.

Perhaps an opDispatch can help, but seems an awful lot to avoid explicit 
passing of this variable.

-Steve