• Andrey Zherikov (15/15) Oct 22 2020 There are two ways how __FILE__, __LINE__ etc. can se used in
• H. S. Teoh (12/16) Oct 22 2020 I don't know what's the "recommended" way, but generally, I prefer to
• Mathias LANG (4/21) Oct 22 2020 You will. This is possible since v2.079.0 (March 2018):
• Andrey Zherikov (1/1) Oct 22 2020 Thanks for all your answers!

Andrey Zherikov <andrey.zherikov gmail.com> writes:

There are two ways how __FILE__, __LINE__ etc. can se used in 
function parameters: as regular parameters and as template 
parameters:

void rt(string file=__FILE__, int line=__LINE__, string 
func=__FUNCTION__)
{
     writeln(file,"(",line,"): ",func);
}

void ct(string file=__FILE__, int line=__LINE__, string 
func=__FUNCTION__)()
{
     writeln(file,"(",line,"): ",func);
}

What is recommended way?
What are pros/cons of each case?

"H. S. Teoh" <hsteoh quickfur.ath.cx> writes:

On Thu, Oct 22, 2020 at 03:32:57PM +0000, Andrey Zherikov via
Digitalmars-d-learn wrote:
 There are two ways how __FILE__, __LINE__ etc. can se used in function
 parameters: as regular parameters and as template parameters:

[...]
 What is recommended way?
 What are pros/cons of each case?

I don't know what's the "recommended" way, but generally, I prefer to
pass them as regular parameters. Otherwise you will get a lot of
template bloat: one instantiation per file/line combination.

However, sometimes there is not much choice: if your function is
variadic, then you pretty much have to use template parameters, 'cos
otherwise you won't be able to pick up the __FILE__/__LINE__ of the
caller with default arguments.


T

-- 
Knowledge is that area of ignorance that we arrange and classify. -- Ambrose
Bierce

Mathias LANG <geod24 gmail.com> writes:

On Thursday, 22 October 2020 at 16:03:45 UTC, H. S. Teoh wrote:
 On Thu, Oct 22, 2020 at 03:32:57PM +0000, Andrey Zherikov via 
 Digitalmars-d-learn wrote:
 There are two ways how __FILE__, __LINE__ etc. can se used in 
 function parameters: as regular parameters and as template 
 parameters:

 [...]
 What is recommended way?
 What are pros/cons of each case?

 I don't know what's the "recommended" way, but generally, I 
 prefer to pass them as regular parameters. Otherwise you will 
 get a lot of template bloat: one instantiation per file/line 
 combination.

 However, sometimes there is not much choice: if your function 
 is variadic, then you pretty much have to use template 
 parameters, 'cos otherwise you won't be able to pick up the 
 __FILE__/__LINE__ of the caller with default arguments.


 T

You will. This is possible since v2.079.0 (March 2018): 
https://dlang.org/changelog/2.079.0.html#default_after_variadic
So yeah, always pass them as function parameters to avoid bloat.

Andrey Zherikov <andrey.zherikov gmail.com> writes:

Thanks for all your answers!