Generic procedure

[Milsa]

I want to rewrite this code to generic code:
https://wiki.freepascal.org/Array_sort
I have problem with this code:

Code: Pascal  [Select][+][-]

1. unit SortGeneric;
2.  
3. {$mode objfpc}{$H+}
4.  
5. interface
6.  
7. uses
8.   Classes, SysUtils;
9.  
10. type
11.   generic TCompareFunc<T> = function (const elem1, elem2: T): Integer;
12.  
13. generic procedure Sort<T>(var Arr: array of T; Count: Integer; CompareFunc: TCompareFunc);
14.  
15. implementation
16.  
17.  
18. end.
19.  

I have message from compiler:

sortgeneric.pas(13,9) Fatal: Syntax error, "identifier" expected but "PROCEDURE" found

My source code is good because this code is in this post:
https://forum.lazarus.freepascal.org/index.php/topic,33327.msg215780.html#msg215780
But it does not work. Why?

[MarkMLl]

What version of compiler?

MarkMLl

[Milsa]

Lazarus 2.0.8 FPC 3.0.4.

[MarkMLl]

The thread you cite EXPLICITLY says that it needs later than 3.0.x. Try trunk or the 3.2 release candidate.

Also https://forum.lazarus.freepascal.org/index.php/topic,50024.msg364222.html#msg364222

MarkMLl

[Milsa]

Solution with 3.0.4 is only with generic class?

[howardpc]

The way you have written it, the T in TCompareFunc<T> is completely unrelated to the T in Sort<T>.
So, irrespective of compiler version, these two unrelated routines cannot work together.
I think you must wrap them in a class or record so there is only a single T known by the two routines.

[bytebites]

OP's code does not compile (with trunk), since specializate is missing.

Code: Pascal  [Select][+][-]

1. unit SortGeneric;
2.  
3. {$mode objfpc}{$H+}
4.  
5. interface
6.  
7. uses
8.   Classes, SysUtils;
9.  
10. type
11.   generic TCompareFunc<T> = function (const elem1, elem2: T): Integer;
12.  
13. generic procedure Sort<T>(var Arr: array of T; Count: Integer; CompareFunc:specialize TCompareFunc<T>);
14.  
15. implementation
16.  
17. generic procedure Sort<T>(var Arr: array of T; Count: Integer; CompareFunc:specialize TCompareFunc<T>);
18. begin
19. end;
20.  
21. end.