intptr_t, uintptr_t - integer types wide enough to hold pointers

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.

       C99, POSIX.1-2001.

       Standard C library (libc)

       intptr_t, uintptr_t - integer types wide enough to hold pointers

       The following header also provides these types: <inttypes.h>.

intmax_t(3type), void(3)

Linux man-pages 6.9.1                              2024-05-02                                    intptr_t(3type)

       C11, POSIX.1-2008.

#include<stdint.h>typedef /* ... */ intptr_t;typedef /* ... */ uintptr_t;#defineINTPTR_WIDTH  /* ... */
       #defineUINTPTR_WIDTHINTPTR_WIDTH#defineINTPTR_MAX    /*  2**(INTPTR_WIDTH - 1) - 1  */
       #defineINTPTR_MIN    /*  - 2**(INTPTR_WIDTH - 1)    */
       #defineUINTPTR_MAX   /*  2**UINTPTR_WIDTH - 1       */