(Overload) Generic procedure

[trexet]

Hi again. I'm trying to make a generic procedure, which is overloaded using generic class:

Code: Pascal  [Select][+][-]

1. interface
2.  
3.     {...}
4.  
5.     generic procedure InitLC<T: TEntity>(LC: specialize TLC_EL_Connector<T>;
6.                                          OwnerBox: TGroupBox;
7.                                          LCCActions: TLCCActions); overload;
8.     generic procedure InitLC<T: TEntity>(LC: specialize TLC_IDL_Connector<T>;
9.                                          OwnerBox: TGroupBox;
10.                                          LCCActions: TLCCActions); overload;
11.  
12. implementation
13.  
14. generic procedure InitLC<T: TEntity>(LC: specialize TLC_EL_Connector<T>;
15.                                      OwnerBox: TGroupBox;
16.                                      LCCActions: TLCCActions);
17. begin
18.  
19. end;
20.  
21. generic procedure InitLC<T: TEntity>(LC: specialize TLC_IDL_Connector<T>;
22.                                      OwnerBox: TGroupBox;
23.                                      LCCActions: TLCCActions);
24. begin
25.  
26. end;

However,

editor.pas(70,23) Error: Forward declaration not solved "InitLC$1(TLC_EL_Connector$1$crcFB7CCBD1;TGroupBox;TLCCActions);"
editor.pas(73,23) Error: Forward declaration not solved "InitLC$1(TLC_IDL_Connector$1$crcD479001B;TGroupBox;TLCCActions);"

UPD: Seems that is has nothing to do with overload. Declaring the procedures as InitLC1 and InitLC2 makes the same error.

FPC 3.2.2, Lazarus 3.4

[Thaddy]

You can not overload generics, because they are generic.
This is also not possible in languages like C++.

[trexet]

You can not overload generics

No, I can. Tested it around and found the following works (mode delphi, with mode objfpc and correct syntax works as well):

Code: Pascal  [Select][+][-]

1. implementation
2.  
3. procedure InitLC<T: TEntity>(var LC: TLC_EL_Connector<T>;
4.     constref OwnerBox: TGroupBox; constref LCCActions: TLCCActions); overload;
5. begin
6.     {...}
7. end;
8.  
9. procedure InitLC<T: TEntity>(var LC: TLC_IDL_Connector<T>;
10.     constref OwnerBox: TGroupBox; constref LCCActions: TLCCActions); overload;
11. begin
12.     {...}
13. end;

Although, declaring the procedures in the interface won't work. Good thing I didn't need that.

This is also not possible in languages like C++.

Absolutely possible:

Code: C  [Select][+][-]

1. template<typename T>
2. T f(int x, T y);
3.  
4. template<typename T>
5. T f(double x, T y);
6.  
7. int main()
8. {
9.     std::printf("f<int>(int) %d\nf<double>(int) %f\nf<int>(double) %d\nf<double>(double) %f\n",
10.                 f<int>(1, 1),
11.                 f<double>(1, 1.0),
12.                 f<int>(1.0, 1),
13.                 f<double>(1.0, 1.0));
14.  
15.     return 0;
16. }
17.  
18. template<typename T>
19. T f(int x, T y) {
20.     return x + y;
21. }
22.  
23. template<typename T>
24. T f(double x, T y) {
25.     return x - y;
26. }

[PascalDragon]

Hi again. I'm trying to make a generic procedure, which is overloaded using generic class:

The problem is that constraints currently aren't handled correctly to correctly match the implementation to the declaration. It's on my todo-list, but it's a bit involved solve...

As a workaround you could make these functions instead static non-generic methods of a generic record which can then have the constraint.