Function Template for Dynamic Parameter

[vino.B]

On Sunday, 1 July 2018 at 11:52:19 UTC, Alex wrote:
> On Sunday, 1 July 2018 at 11:19:50 UTC, vino.B wrote:
>>
>> Hi Timoses,
>>
>>   Thank you very much, can you help me on how to rewrite the 
>> below using Variadic template
>>
>> Passing function as a parameter to another function:
>>
>> void ptFun(T)(T function(string, string, int) coRoutine, 
>> Array!string Dirlst, ) {
>> alias scRType = typeof(coRoutine(string.init, string.init, 
>> int.init));
>>
>> where the "function(string, string, int) coRoutine" should be 
>> a variadic function
>>
>> From,
>> Vino.B
>
> I'm not sure, if get your question right, is this what you are 
> looking for?
>
>
> ´´´
> import std.stdio;
> import std.traits;
>
> void main()
> {
> 	alias instantiation = ptFun!(size_t, fun!string);
> 	
> 	instantiation(4);
>
> 	alias instantiation2 = ptFun2!(fun!string);
>
> 	instantiation2(4);
>
> }
>
> auto fun(T...)(T input)
> {
> 	return size_t(42);
> }
>
> void ptFun(T, alias funToCall)(size_t definedParam)
> 	if(is(T == ReturnType!(funToCall)))
> {
> 	"ptFun called".writeln;
> 	assert(42 == funToCall("some string"));
> }
>
> void ptFun2(alias funToCall)(size_t definedParam)
> 	if(__traits(isSame, TemplateOf!(funToCall), fun))
> {
> 	"ptFun2 called".writeln;
> 	assert(42 == funToCall("some string"));
> }
> ´´´

Hi Alex,

   Something similar to the below code, when compling the below 
code i get an error

NewType.d(19): Error: function declaration without return type. 
(Note that constructors are always named this)

import core.time: days;
import std.algorithm: each, filter, map, sort, strip;
import std.container.array;
import std.conv: to;
import std.datetime.systime: Clock, SysTime;
import std.file: dirEntries, isFile, SpanMode;
import std.parallelism: parallel;
import std.stdio: File, writefln, writeln;
import std.string: strip;
import std.traits: ReturnType;
import std.typecons: Tuple, tuple;

auto coCleanFiles(T ...)(T args) {
	auto dFiles = Array!(Tuple!(string, SysTime))(dirEntries(FFs, 
SpanMode.shallow).filter!(a => a.isFile).map!(a => tuple(a.name, 
a.timeLastModified)));
	return dFiles;
}

void ptManagecoRoutine(T)(T function(T ...)(T args), Array!string 
Dirlst) {
     alias scRType = typeof(coRoutine(args.init));
     auto PFresult = taskPool.workerLocalStorage!scRType;
     ReturnType!coRoutine rData;
     foreach (string FFs; Dirlst[]) { PFresult.get ~= 
coRoutine(FFs.strip); }
     foreach(i; PFresult.toRange) { rData ~= i[][]; }
     if (!rData[].empty) { rData[].sort!((a,b) => a[1] < 
b[1]).each!(e => writefln!"%-83s %.20s"(e[0], e[1].to!string)); }
}
  void main () {
  Array!string CleanDirlst;
  CleanDirlst.insertBack("C:\\Temp\\BACKUP1");
  ptManagecoRoutine(&coCleanFiles, CleanDirlst);
  }

From,
Vino.B