<stdint.h>: Standard Integer Types

Exact-width integer types
Integer types having exactly the specified width.
typedef signed char	int8_t
typedef unsigned char	uint8_t
typedef signed int	int16_t
typedef unsigned int	uint16_t
typedef __int24	int24_t
typedef __uint24	uint24_t
typedef signed long int	int32_t
typedef unsigned long int	uint32_t
typedef signed long long int	int64_t
typedef unsigned long long int	uint64_t

Integer types capable of holding object pointers
These allow you to declare variables of the same size as a pointer.
typedef int16_t	intptr_t
typedef uint16_t	uintptr_t
typedef int_least24_t	intptr24_t
typedef uint_least24_t	uintptr24_t

Minimum-width integer types
Integer types having at least the specified width.
typedef int8_t	int_least8_t
typedef uint8_t	uint_least8_t
typedef int16_t	int_least16_t
typedef uint16_t	uint_least16_t
typedef int24_t	int_least24_t
typedef uint24_t	uint_least24_t
typedef int32_t	int_least32_t
typedef uint32_t	uint_least32_t
typedef int64_t	int_least64_t
typedef uint64_t	uint_least64_t

Fastest minimum-width integer types
Integer types being usually fastest having at least the specified width.
typedef int8_t	int_fast8_t
typedef uint8_t	uint_fast8_t
typedef int16_t	int_fast16_t
typedef uint16_t	uint_fast16_t
typedef int24_t	int_fast24_t
typedef uint24_t	uint_fast24_t
typedef int32_t	int_fast32_t
typedef uint32_t	uint_fast32_t
typedef int64_t	int_fast64_t
typedef uint64_t	uint_fast64_t

Greatest-width integer types
Types designating integer data capable of representing any value of any integer type in the corresponding signed or unsigned category.
typedef int64_t	intmax_t
typedef uint64_t	uintmax_t

Limits of specified-width integer types
C++ implementations should define these macros only when __STDC_LIMIT_MACROS is defined before <stdint.h> is included.
#define	INT8_MAX   0x7f
#define	INT8_MIN   (-INT8_MAX - 1)
#define	UINT8_MAX   (__CONCAT(INT8_MAX, U) * 2U + 1U)
#define	INT16_MAX   0x7fff
#define	INT16_MIN   (-INT16_MAX - 1)
#define	UINT16_MAX   (__CONCAT(INT16_MAX, U) * 2U + 1U)
#define	INT24_MAX   __INT24_MAX__
#define	INT24_MIN   __INT24_MIN__
#define	UINT24_MAX   __UINT24_MAX__
#define	INT32_MAX   0x7fffffffL
#define	INT32_MIN   (-INT32_MAX - 1L)
#define	UINT32_MAX   (__CONCAT(INT32_MAX, U) * 2UL + 1UL)
#define	INT64_MAX   0x7fffffffffffffffLL
#define	INT64_MIN   (-INT64_MAX - 1LL)
#define	UINT64_MAX   (__CONCAT(INT64_MAX, U) * 2ULL + 1ULL)

Limits of minimum-width integer types
#define	INT_LEAST8_MAX   INT8_MAX
#define	INT_LEAST8_MIN   INT8_MIN
#define	UINT_LEAST8_MAX   UINT8_MAX
#define	INT_LEAST16_MAX   INT16_MAX
#define	INT_LEAST16_MIN   INT16_MIN
#define	UINT_LEAST16_MAX   UINT16_MAX
#define	INT_LEAST24_MAX   INT24_MAX
#define	INT_LEAST24_MIN   INT24_MIN
#define	UINT_LEAST24_MAX   UINT24_MAX
#define	INT_LEAST32_MAX   INT32_MAX
#define	INT_LEAST32_MIN   INT32_MIN
#define	UINT_LEAST32_MAX   UINT32_MAX
#define	INT_LEAST64_MAX   INT64_MAX
#define	INT_LEAST64_MIN   INT64_MIN
#define	UINT_LEAST64_MAX   UINT64_MAX

Limits of fastest minimum-width integer types
#define	INT_FAST8_MAX   INT8_MAX
#define	INT_FAST8_MIN   INT8_MIN
#define	UINT_FAST8_MAX   UINT8_MAX
#define	INT_FAST16_MAX   INT16_MAX
#define	INT_FAST16_MIN   INT16_MIN
#define	UINT_FAST16_MAX   UINT16_MAX
#define	INT_FAST24_MAX   INT24_MAX
#define	INT_FAST24_MIN   INT24_MIN
#define	UINT_FAST24_MAX   UINT24_MAX
#define	INT_FAST32_MAX   INT32_MAX
#define	INT_FAST32_MIN   INT32_MIN
#define	UINT_FAST32_MAX   UINT32_MAX
#define	INT_FAST64_MAX   INT64_MAX
#define	INT_FAST64_MIN   INT64_MIN
#define	UINT_FAST64_MAX   UINT64_MAX

Limits of integer types capable of holding object pointers
#define	INTPTR_MAX   INT16_MAX
#define	INTPTR_MIN   INT16_MIN
#define	UINTPTR_MAX   UINT16_MAX
#define	INTPTR24_MAX   INT24_MAX
#define	INTPTR24_MIN   INT24_MIN
#define	UINTPTR24_MAX   UINT24_MAX

Limits of greatest-width integer types
#define	INTMAX_MAX   INT64_MAX
#define	INTMAX_MIN   INT64_MIN
#define	UINTMAX_MAX   UINT64_MAX

Limits of other integer types
C++ implementations should define these macros only when __STDC_LIMIT_MACROS is defined before <stdint.h> is included.
#define	PTRDIFF_MAX   INT16_MAX
#define	PTRDIFF_MIN   INT16_MIN
#define	SIG_ATOMIC_MAX   INT8_MAX
#define	SIG_ATOMIC_MIN   INT8_MIN
#define	SIZE_MAX   UINT16_MAX

Macros for integer constants
C++ implementations should define these macros only when __STDC_CONSTANT_MACROS is defined before <stdint.h> is included. These definitions are valid for integer constants without suffix and for macros defined as integer constant without suffix.
#define	INT8_C(value)   ((int8_t) value)
#define	UINT8_C(value)   ((uint8_t) __CONCAT(value, U))
#define	INT16_C(value)   value
#define	UINT16_C(value)   __CONCAT(value, U)
#define	INT24_C(value)   ((int24_t) __CONCAT(value, L))
#define	UINT24_C(value)   ((uint24_t) __CONCAT(value, UL))
#define	INT32_C(value)   __CONCAT(value, L)
#define	UINT32_C(value)   __CONCAT(value, UL)
#define	INT64_C(value)   __CONCAT(value, LL)
#define	UINT64_C(value)   __CONCAT(value, ULL)
#define	INTMAX_C(value)   __CONCAT(value, LL)
#define	UINTMAX_C(value)   __CONCAT(value, ULL)

Detailed Description

#include <stdint.h> 

Use [u]intN_t if you need exactly N bits.

Since these typedefs are mandated by the C99 standard, they are preferred over rolling your own typedefs.

Note

The 24-bit types and constants are supported since AVR-LibC v2.3. In older versions, they can still be used by means of the compiler built-in types and macros __int24, __uint24, __INT24_MIN__, __INT24_MAX__ and __UINT24_MAX__ supported since GCC v4.7.

Macro Definition Documentation

INT16_C

#define INT16_C

(

value

)

value

Define a constant of type int16_t

INT16_MAX

#define INT16_MAX   0x7fff

Largest positive value an int16_t can hold.

INT16_MIN

#define INT16_MIN   (-INT16_MAX - 1)

Smallest negative value an int16_t can hold.

INT24_C

#define INT24_C

(

value

)

((int24_t) __CONCAT(value, L))

Define a constant of type int24_t

Since

AVR-LibC v2.3, int24

INT24_MAX

#define INT24_MAX   __INT24_MAX__

Largest positive value an int24_t can hold.

Since

AVR-LibC v2.3, int24

INT24_MIN

#define INT24_MIN   __INT24_MIN__

Smallest negative value an int24_t can hold.

Since

AVR-LibC v2.3, int24

INT32_C

#define INT32_C

(

value

)

__CONCAT(value, L)

Define a constant of type int32_t

INT32_MAX

#define INT32_MAX   0x7fffffffL

Largest positive value an int32_t can hold.

INT32_MIN

#define INT32_MIN   (-INT32_MAX - 1L)

Smallest negative value an int32_t can hold.

INT64_C

#define INT64_C

(

value

)

__CONCAT(value, LL)

Define a constant of type int64_t

INT64_MAX

#define INT64_MAX   0x7fffffffffffffffLL

Largest positive value an int64_t can hold.

INT64_MIN

#define INT64_MIN   (-INT64_MAX - 1LL)

Smallest negative value an int64_t can hold.

INT8_C

#define INT8_C

(

value

)

((int8_t) value)

Define a constant of type int8_t

INT8_MAX

#define INT8_MAX   0x7f

Largest positive value an int8_t can hold.

INT8_MIN

#define INT8_MIN   (-INT8_MAX - 1)

Smallest negative value an int8_t can hold.

INT_FAST16_MAX

#define INT_FAST16_MAX   INT16_MAX

Largest positive value an int_fast16_t can hold.

INT_FAST16_MIN

#define INT_FAST16_MIN   INT16_MIN

Smallest negative value an int_fast16_t can hold.

INT_FAST24_MAX

#define INT_FAST24_MAX   INT24_MAX

Largest positive value an int_fast24_t can hold.

Since

AVR-LibC v2.3, int24

INT_FAST24_MIN

#define INT_FAST24_MIN   INT24_MIN

Smallest negative value an int_fast24_t can hold.

Since

AVR-LibC v2.3, int24

INT_FAST32_MAX

#define INT_FAST32_MAX   INT32_MAX

Largest positive value an int_fast32_t can hold.

INT_FAST32_MIN

#define INT_FAST32_MIN   INT32_MIN

Smallest negative value an int_fast32_t can hold.

INT_FAST64_MAX

#define INT_FAST64_MAX   INT64_MAX

Largest positive value an int_fast64_t can hold.

INT_FAST64_MIN

#define INT_FAST64_MIN   INT64_MIN

Smallest negative value an int_fast64_t can hold.

INT_FAST8_MAX

#define INT_FAST8_MAX   INT8_MAX

Largest positive value an int_fast8_t can hold.

INT_FAST8_MIN

#define INT_FAST8_MIN   INT8_MIN

Smallest negative value an int_fast8_t can hold.

INT_LEAST16_MAX

#define INT_LEAST16_MAX   INT16_MAX

Largest positive value an int_least16_t can hold.

INT_LEAST16_MIN

#define INT_LEAST16_MIN   INT16_MIN

Smallest negative value an int_least16_t can hold.

INT_LEAST24_MAX

#define INT_LEAST24_MAX   INT24_MAX

Largest positive value an int_least24_t can hold.

Since

AVR-LibC v2.3, int24

INT_LEAST24_MIN

#define INT_LEAST24_MIN   INT24_MIN

Smallest negative value an int_least24_t can hold.

Since

AVR-LibC v2.3, int24

INT_LEAST32_MAX

#define INT_LEAST32_MAX   INT32_MAX

Largest positive value an int_least32_t can hold.

INT_LEAST32_MIN

#define INT_LEAST32_MIN   INT32_MIN

Smallest negative value an int_least32_t can hold.

INT_LEAST64_MAX

#define INT_LEAST64_MAX   INT64_MAX

Largest positive value an int_least64_t can hold.

INT_LEAST64_MIN

#define INT_LEAST64_MIN   INT64_MIN

Smallest negative value an int_least64_t can hold.

INT_LEAST8_MAX

#define INT_LEAST8_MAX   INT8_MAX

Largest positive value an int_least8_t can hold.

INT_LEAST8_MIN

#define INT_LEAST8_MIN   INT8_MIN

Smallest negative value an int_least8_t can hold.

INTMAX_C

#define INTMAX_C

(

value

)

__CONCAT(value, LL)

Define a constant of type intmax_t

INTMAX_MAX

#define INTMAX_MAX   INT64_MAX

Largest positive value an intmax_t can hold.

INTMAX_MIN

#define INTMAX_MIN   INT64_MIN

Smallest negative value an intmax_t can hold.

INTPTR24_MAX

#define INTPTR24_MAX   INT24_MAX

Largest positive value an intptr24_t can hold.

Since

AVR-LibC v2.3, int24

INTPTR24_MIN

#define INTPTR24_MIN   INT24_MIN

Smallest negative value an intptr24_t can hold.

Since

AVR-LibC v2.3, int24

INTPTR_MAX

#define INTPTR_MAX   INT16_MAX

Largest positive value an intptr_t can hold.

INTPTR_MIN

#define INTPTR_MIN   INT16_MIN

Smallest negative value an intptr_t can hold.

PTRDIFF_MAX

#define PTRDIFF_MAX   INT16_MAX

Largest positive value a ptrdiff_t can hold.

PTRDIFF_MIN

#define PTRDIFF_MIN   INT16_MIN

Smallest negative value a ptrdiff_t can hold.

SIG_ATOMIC_MAX

#define SIG_ATOMIC_MAX   INT8_MAX

Largest positive value a sig_atomic_t can hold.

SIG_ATOMIC_MIN

#define SIG_ATOMIC_MIN   INT8_MIN

Smallest negative value a sig_atomic_t can hold.

SIZE_MAX

#define SIZE_MAX   UINT16_MAX

Largest value a size_t can hold.

UINT16_C

#define UINT16_C

(

value

)

__CONCAT(value, U)

Define a constant of type uint16_t

UINT16_MAX

#define UINT16_MAX   (__CONCAT(INT16_MAX, U) * 2U + 1U)

Largest value an uint16_t can hold.

UINT24_C

#define UINT24_C

(

value

)

((uint24_t) __CONCAT(value, UL))

Define a constant of type uint24_t

Since

AVR-LibC v2.3, int24

UINT24_MAX

#define UINT24_MAX   __UINT24_MAX__

Largest value an uint24_t can hold.

Since

AVR-LibC v2.3, int24

UINT32_C

#define UINT32_C

(

value

)

__CONCAT(value, UL)

Define a constant of type uint32_t

UINT32_MAX

#define UINT32_MAX   (__CONCAT(INT32_MAX, U) * 2UL + 1UL)

Largest value an uint32_t can hold.

UINT64_C

#define UINT64_C

(

value

)

__CONCAT(value, ULL)

Define a constant of type uint64_t

UINT64_MAX

#define UINT64_MAX   (__CONCAT(INT64_MAX, U) * 2ULL + 1ULL)

Largest value an uint64_t can hold.

UINT8_C

#define UINT8_C

(

value

)

((uint8_t) __CONCAT(value, U))

Define a constant of type uint8_t

UINT8_MAX

#define UINT8_MAX   (__CONCAT(INT8_MAX, U) * 2U + 1U)

Largest value an uint8_t can hold.

UINT_FAST16_MAX

#define UINT_FAST16_MAX   UINT16_MAX

Largest value an uint_fast16_t can hold.

UINT_FAST24_MAX

#define UINT_FAST24_MAX   UINT24_MAX

Largest value an uint_fast24_t can hold.

Since

AVR-LibC v2.3, int24

UINT_FAST32_MAX

#define UINT_FAST32_MAX   UINT32_MAX

Largest value an uint_fast32_t can hold.

UINT_FAST64_MAX

#define UINT_FAST64_MAX   UINT64_MAX

Largest value an uint_fast64_t can hold.

UINT_FAST8_MAX

#define UINT_FAST8_MAX   UINT8_MAX

Largest value an uint_fast8_t can hold.

UINT_LEAST16_MAX

#define UINT_LEAST16_MAX   UINT16_MAX

Largest value an uint_least16_t can hold.

UINT_LEAST24_MAX

#define UINT_LEAST24_MAX   UINT24_MAX

Largest value an uint_least24_t can hold.

Since

AVR-LibC v2.3, int24

UINT_LEAST32_MAX

#define UINT_LEAST32_MAX   UINT32_MAX

Largest value an uint_least32_t can hold.

UINT_LEAST64_MAX

#define UINT_LEAST64_MAX   UINT64_MAX

Largest value an uint_least64_t can hold.

UINT_LEAST8_MAX

#define UINT_LEAST8_MAX   UINT8_MAX

Largest value an uint_least8_t can hold.

UINTMAX_C

#define UINTMAX_C

(

value

)

__CONCAT(value, ULL)

Define a constant of type uintmax_t

UINTMAX_MAX

#define UINTMAX_MAX   UINT64_MAX

Largest value an uintmax_t can hold.

UINTPTR24_MAX

#define UINTPTR24_MAX   UINT24_MAX

Largest value an uintptr24_t can hold.

Since

AVR-LibC v2.3, int24

UINTPTR_MAX

#define UINTPTR_MAX   UINT16_MAX

Largest value an uintptr_t can hold.

Typedef Documentation

int16_t

typedef signed int int16_t

16-Bit signed integer type.

int24_t

typedef __int24 int24_t

24-Bit signed integer type.

Since

AVR-LibC v2.3, int24

int32_t

typedef signed long int int32_t

32-Bit signed integer type.

int64_t

typedef signed long long int int64_t

64-Bit signed integer type.

Note

This type is not available when the compiler option -mint8 is in effect.

int8_t

typedef signed char int8_t

8-Bit signed integer type.

int_fast16_t

typedef int16_t int_fast16_t

Fastest signed integer type with at least 16 bits.

int_fast24_t

typedef int24_t int_fast24_t

Fastest signed integer type with at least 24 bits.

Since

AVR-LibC v2.3, int24

int_fast32_t

typedef int32_t int_fast32_t

Fastest signed integer type with at least 32 bits.

int_fast64_t

typedef int64_t int_fast64_t

Fastest signed integer type with at least 64 bits.

Note

This type is not available when the compiler option -mint8 is in effect.

int_fast8_t

typedef int8_t int_fast8_t

Fastest signed integer type with at least 8 bits.

int_least16_t

typedef int16_t int_least16_t

Signed integer type with at least 16 bits.

int_least24_t

typedef int24_t int_least24_t

Signed integer type with at least 24 bits.

Since

AVR-LibC v2.3, int24

int_least32_t

typedef int32_t int_least32_t

Signed integer type with at least 32 bits.

int_least64_t

typedef int64_t int_least64_t

Signed integer type with at least 64 bits.

Note

This type is not available when the compiler option -mint8 is in effect.

int_least8_t

typedef int8_t int_least8_t

Signed integer type with at least 8 bits.

intmax_t

typedef int64_t intmax_t

Largest signed integer available.

intptr24_t

typedef int_least24_t intptr24_t

Signed 24-bit pointer compatible type.

Since

AVR-LibC v2.3, int24

intptr_t

typedef int16_t intptr_t

Signed pointer compatible type.

uint16_t

typedef unsigned int uint16_t

16-Bit unsigned integer type.

uint24_t

typedef __uint24 uint24_t

24-Bit unsigned integer type.

Since

AVR-LibC v2.3, int24

uint32_t

typedef unsigned long int uint32_t

32-Bit unsigned integer type.

uint64_t

typedef unsigned long long int uint64_t

64-Bit unsigned integer type.

Note

This type is not available when the compiler option -mint8 is in effect.

uint8_t

typedef unsigned char uint8_t

8-Bit unsigned integer type.

uint_fast16_t

typedef uint16_t uint_fast16_t

Fastest unsigned integer type with at least 16 bits.

uint_fast24_t

typedef uint24_t uint_fast24_t

Fastest unsigned integer type with at least 24 bits.

Since

AVR-LibC v2.3, int24

uint_fast32_t

typedef uint32_t uint_fast32_t

Fastest unsigned integer type with at least 32 bits.

uint_fast64_t

typedef uint64_t uint_fast64_t

Fastest unsigned integer type with at least 64 bits.

Note

This type is not available when the compiler option -mint8 is in effect.

uint_fast8_t

typedef uint8_t uint_fast8_t

Fastest unsigned integer type with at least 8 bits.

uint_least16_t

typedef uint16_t uint_least16_t

Unsigned integer type with at least 16 bits.

uint_least24_t

typedef uint24_t uint_least24_t

Unsigned integer type with at least 24 bits.

Since

AVR-LibC v2.3, int24

uint_least32_t

typedef uint32_t uint_least32_t

Unsigned integer type with at least 32 bits.

uint_least64_t

typedef uint64_t uint_least64_t

Unsigned integer type with at least 64 bits.

Note

This type is not available when the compiler option -mint8 is in effect.

uint_least8_t

typedef uint8_t uint_least8_t

Unsigned integer type with at least 8 bits.

uintmax_t

typedef uint64_t uintmax_t

Largest unsigned integer available.

uintptr24_t

typedef uint_least24_t uintptr24_t

Unsigned 24-bit pointer compatible type.

Since

AVR-LibC v2.3, int24

uintptr_t

typedef uint16_t uintptr_t

Unsigned pointer compatible type.