[next] [prev] [prev-tail] [tail] [up]

### 6.5 The @ operator

The address operator @ returns the address of a variable, procedure or function. It is used as follows:

_________________________________________________________________________________________________________ Address factor
___________________________________________________________________

The @ operator returns a typed pointer if the $T switch is on. If the $T switch is off then the address operator returns an untyped pointer, which is assigment compatible with all pointer types. The type of the pointer is ^T, where T is the type of the variable reference. For example, the following will compile

     Program tcast;
     {$T-} { @ returns untyped pointer }

     Type art = Array[1..100] of byte;
     Var Buffer : longint;
         PLargeBuffer : ^art;

     begin
      PLargeBuffer := @Buffer;
     end.

Changing the {$T-} to {$T+} will prevent the compiler from compiling this. It will give a type mismatch error. By default, the address operator returns an untyped pointer. Applying the address operator to a function, method, or procedure identifier will give a pointer to the entry point of that function. The result is an untyped pointer. By default, the address operator must be used if a value must be assigned to a procedural type variable. This behaviour can be avoided by using the -So or -S2 switches, which result in a more compatible Delphi or Turbo Pascal syntax.

[next] [prev] [prev-tail] [front] [up]