Fix Delphi compatibility

Author: michaliskambi

code-samples/generics_lists.dpr

@@ -8,7 +8,7 @@ type
     Name: string;
   end;
 
-  TAppleList = specialize TObjectList<TApple>;
+  TAppleList = {$ifdef FPC_OBJFPC}specialize{$endif} TObjectList<TApple>;
 
 var
   A: TApple;

code-samples/generics_sorting.dpr

@@ -18,7 +18,7 @@ type
     Name: string;
   end;
 
-  TAppleList = specialize TObjectList<TApple>;
+  TAppleList = {$ifdef FPC_OBJFPC}specialize{$endif} TObjectList<TApple>;
 
 function CompareApples(
   {$ifdef GENERICS_CONSTREF}constref{$else}const{$endif}
@@ -28,7 +28,7 @@ begin
 end;
 
 type
-  TAppleComparer = specialize TComparer<TApple>;
+  TAppleComparer = {$ifdef FPC_OBJFPC}specialize{$endif} TComparer<TApple>;
 var
   A: TApple;
   L: TAppleList;
@@ -47,7 +47,7 @@ begin
     A.Name := '22';
     L.Add(A);
 
-    L.Sort(TAppleComparer.Construct(@CompareApples));
+    L.Sort(TAppleComparer.Construct({$ifdef FPC_OBJFPC}@{$endif} CompareApples));
 
     Writeln('Count: ', L.Count);
     Writeln(L[0].Name);

code-samples/interfaces_com_test.dpr

@@ -53,12 +53,14 @@ var
 
 procedure UseInterfaces;
 begin
-  if C1 is IMyInterface then
-  //if Supports(C1, IMyInterface) then // equivalent to "is" check above
+  // In FPC, you could also check using "is", like:
+  //if C1 is IMyInterface then ...
+
+  if Supports(C1, IMyInterface) then
     UseThroughInterface(C1 as IMyInterface);
-  if C2 is IMyInterface then
+  if Supports(C2, IMyInterface) then
     UseThroughInterface(C2 as IMyInterface);
-  if C3 is IMyInterface then
+  if Supports(C3, IMyInterface) then
     UseThroughInterface(C3 as IMyInterface);
 end;