intptr_t - integer types wide enough to hold pointers

NAME LIBRARY SYNOPSIS DESCRIPTION STANDARDS HISTORY NOTES SEE ALSO

NAME

intptr_t, uintptr_t − integer types wide enough to hold pointers

SYNOPSIS

#include <stdint.h>

typedef /* ... */ intptr_t;
typedef /* ... */ uintptr_t;

#define INTPTR_WIDTH /* ... */
#define UINTPTR_WIDTH INTPTR_WIDTH

#define INTPTR_MAX /* 2**(INTPTR_WIDTH − 1) − 1 */
#define INTPTR_MIN /* − 2**(INTPTR_WIDTH − 1) */
#define UINTPTR_MAX /* 2**UINTPTR_WIDTH − 1 */

intptr_t is a signed integer type such that any valid (void *) value can be converted to this type and then converted back. It is capable of storing values in the range [INTPTR_MIN, INTPTR_MAX].

uintptr_t is an unsigned integer type such that any valid (void *) value can be converted to this type and then converted back. It is capable of storing values in the range [0, INTPTR_MAX].

The macros [U]INTPTR_WIDTH expand to the width in bits of these types.

The macros [U]INTPTR_MAX expand to the maximum value that these types can hold.

The macro INTPTR_MIN expands to the minimum value that intptr_t can hold.

The length modifiers for the [u]intptr_t types for the printf(3) family of functions are expanded by the macros PRIdPTR, PRIiPTR, and PRIuPTR (defined in <inttypes.h>); resulting commonly in %"PRIdPTR" or %"PRIiPTR" for printing intptr_t values. The length modifiers for the [u]intptr_t types for the scanf(3) family of functions are expanded by the macros SCNdPTR, SCNiPTR, and SCNuPTR (defined in <inttypes.h>); resulting commonly in %"SCNuPTR" for scanning uintptr_t values.