System.Pointer
Delphi
type Pointer = ^Pointer;
C++
typedef void* Pointer; //
Properties
| Type | Visibility | Source | Unit | Parent |
|---|---|---|---|---|
pointer typedef |
public | System.pas sysmac.h |
System | System |
Description
Address of a byte in memory.
A void pointer represents the address of a byte in memory. Such a pointer cannot be dereferenced, because no type information is associated with it. However, a void pointer can be cast to a typed pointer and then dereferenced.
Variables declared with the specifier register are not located in the main address space and cannot be referenced.
Depending on the pointer value, dereference operation can have various effects:
| Pointer value | Dereference effect |
| address of data | Produces the data value. |
| address of function/procedure | Generates a call to a function/procedure. |
nil/NULL
|
Generates an error or exception. See EAccessViolation. |
| invalid | Undefined result. Indicates a software fault. See EInvalidPointer. |
Pointer reference/dereference operators:
| Delphi | C++ | |
| Reference | @object
|
&object
|
| Dereference | object_pointer^
|
*object_pointer
|
The size of a pointer depends on the operating system and/or the processor. On 32-bit platforms, a pointer is stored on 4 bytes as a 32-bit address. On 64-bit platforms, a pointer is stored on 8 bytes as a 64-bit address.