header

<cstdint> (stdint.h)

Integer types

This header defines a set of integral type aliases with specific width requirements, along with macros specifying their limits and macro functions to create values of these types.

Types

The following are typedefs of fundamental integral types or extended integral types.

signed type	unsigned type	description
`intmax_t`	`uintmax_t`	Integer type with the maximum width supported.
`int8_t`	`uint8_t`	Integer type with a width of exactly 8, 16, 32, or 64 bits. For signed types, negative values are represented using 2's complement. No padding bits. Optional: These typedefs are not defined if no types with such characteristics exist.*
`int16_t`	`uint16_t`
`int32_t`	`uint32_t`
`int64_t`	`uint64_t`
`int_least8_t`	`uint_least8_t`	Integer type with a minimum of 8, 16, 32, or 64 bits. No other integer type exists with lesser size and at least the specified width.
`int_least16_t`	`uint_least16_t`
`int_least32_t`	`uint_least32_t`
`int_least64_t`	`uint_least64_t`
`int_fast8_t`	`uint_fast8_t`	Integer type with a minimum of 8, 16, 32, or 64 bits. At least as fast as any other integer type with at least the specified width.
`int_fast16_t`	`uint_fast16_t`
`int_fast32_t`	`uint_fast32_t`
`int_fast64_t`	`uint_fast64_t`
`intptr_t`	`uintptr_t`	Integer type capable of holding a value converted from a `void` pointer and then be converted back to that type with a value that compares equal to the original pointer. Optional: These typedefs may not be defined in some library implementations.*

Some of these typedefs may denote the same types. Therefore, function overloads should not rely on these being different.

* Notice that some types are optional (and thus, with no portability guarantees). A particular library implementation may also define additional types with other widths supported by its system. In any case, if either the signed or the unsigned version is defined, both the signed and unsigned versions are defined.

Macros

Limits of `cstdint` types

Macro	description	defined as
`INTMAX_MIN`	Minimum value of `intmax_t`	-(2⁶³-1), or lower
`INTMAX_MAX`	Maximum value of `intmax_t`	2⁶³-1, or higher
`UINTMAX_MAX`	Maximum value of `uintmax_t`	2⁶⁴-1, or higher
`INT`N`_MIN`	Minimum value of exact-width signed type	Exactly -2^(N-1)
`INT`N`_MAX`	Maximum value of exact-width signed type	Exactly 2^(N-1)-1
`UINT`N`_MAX`	Maximum value of exact-width unsigned type	Exactly 2^N-1
`INT_LEAST`N`_MIN`	Minimum value of minimum-width signed type	-(2^(N-1)-1), or lower
`INT_LEAST`N`_MAX`	Maximum value of minimum-width signed type	2^(N-1)-1, or higher
`UINT_LEAST`N`_MAX`	Maximum value of minimum-width unsigned type	2^N-1, or higher
`INT_FAST`N`_MIN`	Minimum value of fastest minimum-width signed type	-(2^(N-1)-1), or lower
`INT_FAST`N`_MAX`	Maximum value of fastest minimum-width signed type	2^(N-1)-1, or higher
`UINT_FAST`N`_MAX`	Maximum value of fastest minimum-width unsigned type	2^N-1, or higher
`INTPTR_MIN`	Minimum value of `intptr_t`	-(2¹⁵-1), or lower
`INTPTR_MAX`	Maximum value of `intptr_t`	2¹⁵-1, or higher
`UINTPTR_MAX`	Maximum value of `uintptr_t`	2¹⁶-1, or higher

Where N is one in 8, 16, 32, 64, or any other type width supported by the library.

Only the macros corresponding to types supported by the library are defined.

Limits of other types

Limits of other standard integral types:

Macro	description	defined as
`SIZE_MAX`	Maximum value of `size_t`	2⁶⁴-1, or higher
`PTRDIFF_MIN`	Minimum value of `ptrdiff_t`	-(2¹⁶-1), or lower
`PTRDIFF_MAX`	Maximum value of `ptrdiff_t`	2¹⁶-1, or higher
`SIG_ATOMIC_MIN`	Minimum value of `sig_atomic_t`	if `sig_atomic_t` is signed: -127, or lower if `sig_atomic_t` is unsigned: 0
`SIG_ATOMIC_MAX`	Maximum value of `sig_atomic_t`	if `sig_atomic_t` is signed: 127, or higher if `sig_atomic_t` is unsigned: 255, or higher
`WCHAR_MIN`	Minimum value of `wchar_t`	if `wchar_t` is signed: -127, or lower if `wchar_t` is unsigned: 0
`WCHAR_MAX`	Maximum value of `wchar_t`	if `wchar_t` is signed: 127, or higher if `wchar_t` is unsigned: 255, or higher
`WINT_MIN`	Minimum value of `wint_t`	if `wint_t` is signed: -32767, or lower if `wint_t` is unsigned: 0
`WINT_MAX`	Maximum value of `wint_t`	if `wint_t` is signed: 32767, or higher if `wint_t` is unsigned: 65535, or higher

Function-like macros

These function-like macros expand to integer constants suitable to initialize objects of the types above:

Macro	description
`INTMAX_C`	expands to a value of type `intmax_t`
`UINTMAX_C`	expands to a value of type `uintmax_t`
`INT`N`_C`	expands to a value of type `int_least`N`_t`
`UINT`N`_C`	expands to a value of type `uint_least`N`_t`

For example:

INTMAX_C(2012)  // expands to 2012LL or similar

<cstdint> (stdint.h)

Types

Macros

Limits of `cstdint` types

Limits of other types

Function-like macros

C++

Reference

C library:

Containers:

Input/Output:

Multi-threading:

Other:

<cstdint> (stdint.h)

Types

Macros

Limits of cstdint types

Limits of other types

Function-like macros

C++

Reference

C library:

Containers:

Input/Output:

Multi-threading:

Other:

Limits of `cstdint` types