[Issue 23319] std.range.Generator does not work with non-mutable elements

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=23319

Salih Dincer <salihdb at hotmail.com> changed:

           What    |Removed                     |Added
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                 CC|                            |salihdb at hotmail.com

--- Comment #1 from Salih Dincer <salihdb at hotmail.com> ---
This can be an alternative:

template gen (alias fn) {
  struct GenRes { //
    import std.traits;
    ReturnType!fn func;
    enum empty = false;
    auto front() { return func; }
    void popFront() { func = fn(); }
  }
  GenRes gen() {
    auto gen = GenRes();
         gen.popFront();
    return gen;
  }
} unittest {
  import std.range, std.random : uniform;
  import std.stdio;

  enum E : char { False = 48, True }
  auto r = gen!(function char() => uniform!E);
  r.take(12).writefln!"[%s]";
}
Sources:

https://forum.dlang.org/post/tf0j3c$246r$1@digitalmars.com

https://forum.dlang.org/post/dvtuclqeijpsukxidhlg@forum.dlang.org

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