Joy Online Manual

NAME
objc:offsetPtr - Pointer arithmetic and type casting

SYNOPSIS

objc:offsetPtr address offset ?type?

DESCRIPTION
Returns address + offset * size, where size is the size of type if specified, otherwise the size of address's type. If the optional type parameter is given, the returned pointer points to the specified type, else it has the same type as address.

EXAMPLE
Allocates 100 bytes.

tcl> set p [objc:newPtr {char 100}]
char 100@0x218b78

Adds 100 bytes to $p, returning a pointer to {char 100}.

tcl> objc:offsetPtr $p 1
char 100@0x218bdc

Also adds 100 bytes to $p, returning a pointer to char.

tcl> objc:offsetPtr $p 100 char
char@0x218bdc

Type-casts $p to a pointer to int

tcl> objc:offsetPtr $p 0 int
int@0x218b78

SEE ALSO

objc:newPtr
objc:peek
objc:poke

KEYWORDS
pointer, type

Index