• 0xEAB (3/34) Jul 07 2019 Try: https://run.dlang.io/is/clQgeA
• a11e99z (3/5) Jul 07 2019 probably same
• a11e99z (3/8) Jul 07 2019 oops! this one
• 0xEAB (2/5) Jul 07 2019
• Exil (15/20) Jul 09 2019 Static foreach needs a tuple. When you have a range like "0 ..

0xEAB <desisma heidel.beer> writes:

Why does this `static foreach` lead to hidden usage of operator 
`~=` calls in some cases?

 static foreach(i; 0 .. cnt)

 onlineapp.d(9): Error: cannot use operator ~= in  nogc delegate 
 onlineapp.xv!(myUDA("/")).__funcliteral2.__lambda1




 import std.traits;
 
 private  safe pure nothrow  nogc
 {
     enum xv(alias uda) = function()
     {
         enum cnt = 10;
 
         static foreach(i; 0 .. cnt)
         {
         }
     };
 }
 
 struct myUDA
 {
     string path;
 }
 
  myUDA("/")
 void doSth(string path)
 {
 }
 
 extern(C) void main()
 {
     xv!(getUDAs!(doSth, myUDA))();
 }


Try: https://run.dlang.io/is/clQgeA

a11e99z <black80 bk.ru> writes:

On Sunday, 7 July 2019 at 16:51:57 UTC, 0xEAB wrote:
 Why does this `static foreach` lead to hidden usage of operator 
 `~=` calls in some cases?

probably same 
https://forum.dlang.org/post/qd9ee0$2eud$1 digitalmars.com

a11e99z <black80 bk.ru> writes:

On Sunday, 7 July 2019 at 17:07:59 UTC, a11e99z wrote:
 On Sunday, 7 July 2019 at 16:51:57 UTC, 0xEAB wrote:
 Why does this `static foreach` lead to hidden usage of 
 operator `~=` calls in some cases?

 probably same

oops! this one 
https://forum.dlang.org/post/eidpgqohllwmuumxwrbf forum.dlang.org

0xEAB <desisma heidel.beer> writes:

On Sunday, 7 July 2019 at 16:51:57 UTC, 0xEAB wrote:
 Why does this `static foreach` lead to hidden usage of operator


Further notes by Dan (aka "Wild"):
 I added some small printfs to the compiler, http://ix.io/1NWM
 It seems like it lowers it into something weird

Exil <Exil gmall.com> writes:

On Sunday, 7 July 2019 at 18:45:14 UTC, 0xEAB wrote:
 On Sunday, 7 July 2019 at 16:51:57 UTC, 0xEAB wrote:
 Why does this `static foreach` lead to hidden usage of operator


 Further notes by Dan (aka "Wild"):
 I added some small printfs to the compiler, http://ix.io/1NWM
 It seems like it lowers it into something weird


Static foreach needs a tuple. When you have a range like "0 .. 
10" it has to convert that to a tuple. It does this by generating 
some code and running it at CTFE. Guess this was done as it was a 
lot simpler to do, you don't have to worry about recreating 
ranges as that's already done by using CTFE.

What it ends up lowering to: 
https://github.com/dlang/dmd/blob/v2.087.0/src/dmd/cond.d#L274

      *     static foreach (x; {
      *         typeof({
      *             foreach (x; range) return x;
      *         }())[] __res;
      *         foreach (x; range) __res ~= x;
      *         return __res;
      *     }()) { ... }