"strstr" D equivalent

[pascal111]

On Friday, 29 July 2022 at 15:39:16 UTC, Salih Dincer wrote:
> On Friday, 29 July 2022 at 14:14:54 UTC, pascal111 wrote:
>> we won't find that there is a definition for it with just two 
>> parameters, so from where you got this new definition of this 
>> function?!
>
> This thread is about 
> [UFCS](https://tour.dlang.org/tour/en/gems/uniform-function-call-syntax-ufcs). It can also be written as:
>
> ```d
> import std.string,
>        std.stdio;
>
> void findStr(string str) { }
>
> void main()
> {
>   string str = "Hello, World!";
>   str.indexOf("Wo").writeln; //7
>   auto pos = "Hello, World!".indexOf("Wo");
>
>   auto slice = str[pos..$-1];
>   slice.writeln(": ", slice.length); // World: 5
>   typeid(slice).writeln; // immutable(char)[]
>
>   assert(str.indexOf("Wo") == pos);
>
>   void find_str(string str) { }
>
>   find_str(str);
>   str.findStr();
>
>   /* No compile:
>
>   slice.typeid().writeln;
>
>   slice.indedOf("Wo").assert();
>
>   str.find_str();
>   */
> }
> ```
>
> SDB at 79

I made this version:

auto d_strstr (const string ch, const string substr)
{

         return ch.indexOf(substr);

}

https://github.com/pascal111-fra/D/blob/main/dcollect.d


////////////testing program


module main;

import std.stdio;
import std.string;
import std.conv;
import dcollect;
import std.math;

     int main(string[] args)
     {
         int x;
         char[] ch;
         string ch1="Hello World!";

         writeln(ch1.d_strstr("ll"));


     	return 0;
     }