Re: sorting a mutable array of immutable objects

[Jeff Thompson via Digitalmars-d]

On Wednesday, 20 April 2016 at 12:34:28 UTC, Anonymouse wrote:
On Wednesday, 20 April 2016 at 10:32:42 UTC, Jeff Thompson 
wrote:
On Wednesday, 20 April 2016 at 09:54:13 UTC, Jeff Thompson 
wrote:
I can create a mutable array of immutable objects, thanks to 
the answers to my other question 
https://forum.dlang.org/post/nf57f5$e6v$1...@digitalmars.com .

Now I want to sort the array.

I found a solution, but I'm not sure it is the best way. 
Instead of overriding opCmp, class C just defines a static 
comparison to use with sort (which automatically works with 
Rebindable). Is there a way to do this where I don't need to 
specify C.isLess every time I sort?

class C {
  this(int x) immutable { this.x = x; }
  static bool isLess(const C a, const C b) @safe pure nothrow 
{ return a.x < b.x; }
  int x;
}

void
main(string[] args)
{
  auto array = new Rebindable!(immutable(C))[2];
  array[0] = new immutable C(20);
  array[1] = new immutable C(10);
  sort!(C.isLess)(array);
}

int opCmp(immutable Object o) immutable {}

Thanks for a better solution, but I never would have thought to 
try opCmp without "override" since I assumed that sort was 
looking for the opCmp defined by Object. So many 
counter-intuitive mysteries in D. That's why this forum is 
indipensable.