Phobos: __FILE__ as template default parameter

[ZombineDev via Digitalmars-d]

On Tuesday, 21 June 2016 at 02:59:44 UTC, ZombineDev wrote:
> On Monday, 20 June 2016 at 14:28:06 UTC, Jacob Carlborg wrote:
>> On 2016-06-19 12:43, Dicebot wrote:
>>
>>> Yes. It is necessary because runtime parameter list is 
>>> variadic -
>>> template bloat in such cases is usually eliminated by 
>>> forwarding to
>>> another private method immediately turning file/line into 
>>> first runtime
>>> argument instead.
>>
>> Would it be a bad idea to allow this in the compiler:
>>
>> void foo(Args...)(Args args, string file = __FILE__, size_t 
>> line = __LINE__);
>>
>> It wouldn't be possible to pass "file" or "line" when calling 
>> "foo". But it's useful for the special default values, 
>> __FILE__ and __LINE__.
>
> I think it would be good idea to take this even further:
>
> T4 foo(T4, T0, T1, Ts..., T2, T3)(T0 t0, T1 t1, Args args, T2 
> t2, T3 t3)
>
> In other words, I think that the limitation that variadic 
> template parameter list must be at the end of the function 
> parameters is arbitrary and just a deficiency of the current 
> implementation.
> A fixed number of parameters proceeding or following a variadic 
> list should all work equally well, even in combination with 
> IFTI.
>
> BTW, Ruby also allows to define methods with such parameters: 
> foo(first_arg, *middle_arguments, last_arg)

I meant:

T4 foo(T4, T0, T1, Ts..., T2, T3)(T0 t0, T1 t1, Ts ts, T2 t2, T3 
t3)