Fixed width integer types (since C++11)

 

C++

Language

Standard library headers

Concepts

Utilities library

Strings library

Containers library

Algorithms library

Iterators library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

Filesystem library (C++17)

Technical Specifications

 

Utilities library

Type support (basic types, RTTI, type traits)

Dynamic memory management

Error handling

Program utilities

Variadic functions

Date and time

Function objects

initializer_list (C++11)

bitset

hash (C++11)

Relational operators

rel_ops::operator!=rel_ops::operator>rel_ops::operator<=rel_ops::operator>=

optional, any and variant (C++17)

optional

any

variant

in_placein_place_typein_place_indexin_place_tin_place_type_tin_place_index_t

Pairs and tuples

pair

tuple (C++11)

apply (C++17)

make_from_tuple (C++17)

piecewise_construct_t (C++11)

piecewise_construct (C++11)

integer_sequence (C++14)

Swap, forward and move

swap

exchange (C++14)

forward (C++11)

move (C++11)

move_if_noexcept (C++11)

Elementary string conversions

to_chars (C++17)

from_chars (C++17)

chars_format (C++17)

Type operations

declval (C++11)

as_const (C++17)

 

Type support

Basic types
Fundamental types
Fixed width integer types (C++11)
ptrdiff_t size_t max_align_t (C++11) byte (C++17)	nullptr_t (C++11) offsetof NULL
Numeric limits
numeric_limits
C numeric limits interface
Runtime type information
type_info type_index (C++11)	bad_typeid bad_cast
Type traits
Type categories
is_void (C++11) is_null_pointer (C++14) is_array (C++11) is_pointer (C++11) is_enum (C++11) is_union (C++11) is_class (C++11) is_function (C++11)	is_object (C++11) is_scalar (C++11) is_compound (C++11) is_integral (C++11) is_floating_point (C++11) is_fundamental (C++11) is_arithmetic (C++11)
is_reference (C++11)
is_lvalue_reference (C++11)
is_rvalue_reference (C++11)
is_member_pointer (C++11)
is_member_object_pointer (C++11)
is_member_function_pointer (C++11)

Type properties
is_const (C++11) is_volatile (C++11) is_pod (C++11) is_empty (C++11) is_polymorphic (C++11) is_final (C++14) is_abstract (C++11)	is_trivial (C++11) is_trivially_copyable (C++11) is_standard_layout (C++11) is_literal_type (C++11)(deprecated in C++17) is_aggregate (C++17) is_signed (C++11) is_unsigned (C++11)
has_unique_object_representations (C++17)
Type trait constants
integral_constantbool_constanttrue_typefalse_type (C++11)(C++17)(C++11)(C++11)
Metafunctions
conjunction (C++17)
disjunction (C++17)
negation (C++17)

Supported operations
is_constructibleis_trivially_constructibleis_nothrow_constructible (C++11)(C++11)(C++11)
is_default_constructibleis_trivially_default_constructibleis_nothrow_default_constructible (C++11)(C++11)(C++11)
is_copy_constructibleis_trivially_copy_constructibleis_nothrow_copy_constructible (C++11)(C++11)(C++11)
is_move_constructibleis_trivially_move_constructibleis_nothrow_move_constructible (C++11)(C++11)(C++11)
is_assignableis_trivially_assignableis_nothrow_assignable (C++11)(C++11)(C++11)
is_copy_assignableis_trivially_copy_assignableis_nothrow_copy_assignable (C++11)(C++11)(C++11)
is_move_assignableis_trivially_move_assignableis_nothrow_move_assignable (C++11)(C++11)(C++11)
is_destructibleis_trivially_destructibleis_nothrow_destructible (C++11)(C++11)(C++11)
has_virtual_destructor (C++11)
is_swappable_withis_swappableis_nothrow_swappable_withis_nothrow_swappable (C++17)(C++17)(C++17)(C++17)
Relationships and property queries
is_same (C++11) is_base_of (C++11) is_convertible (C++11)	alignment_of (C++11) rank (C++11) extent (C++11)
is_invocableis_invocable_ris_nothrow_invocableis_nothrow_invocable_r (C++17)(C++17)(C++17)(C++17)
Type modifications
remove_cvremove_constremove_volatile (C++11)(C++11)(C++11) add_cvadd_constadd_volatile (C++11)(C++11)(C++11) make_signed (C++11) make_unsigned (C++11)	remove_reference (C++11) add_lvalue_referenceadd_rvalue_reference (C++11)(C++11) remove_pointer (C++11) add_pointer (C++11) remove_extent (C++11) remove_all_extents (C++11)
Type transformations
aligned_storage (C++11) aligned_union (C++11) decay (C++11) enable_if (C++11) void_t (C++17)	conditional (C++11) common_type (C++11) underlying_type (C++11) result_ofinvoke_result (C++11)(deprecated in C++17)(C++17)

 

Types

Defined in header <cstdint>
int8_tint16_tint32_tint64_t (optional)	signed integer type with width of exactly 8, 16, 32 and 64 bits respectively with no padding bits and using 2's complement for negative values (provided only if the implementation directly supports the type) (typedef)
int_fast8_tint_fast16_tint_fast32_tint_fast64_t	fastest signed integer type with width of at least 8, 16, 32 and 64 bits respectively (typedef)
int_least8_tint_least16_tint_least32_tint_least64_t	smallest signed integer type with width of at least 8, 16, 32 and 64 bits respectively (typedef)
intmax_t	maximum width integer type (typedef)
intptr_t (optional)	integer type capable of holding a pointer (typedef)
uint8_tuint16_tuint32_tuint64_t (optional)	unsigned integer type with width of exactly 8, 16, 32 and 64 bits respectively (provided only if the implementation directly supports the type) (typedef)
uint_fast8_tuint_fast16_tuint_fast32_tuint_fast64_t	fastest unsigned integer type with width of at least 8, 16, 32 and 64 bits respectively (typedef)
uint_least8_tuint_least16_tuint_least32_tuint_least64_t	smallest unsigned integer type with width of at least 8, 16, 32 and 64 bits respectively (typedef)
uintmax_t	maximum width unsigned integer type (typedef)
uintptr_t (optional)	unsigned integer type capable of holding a pointer (typedef)

Macro constants

Defined in header <cstdint>
Signed integers : minimum value
INT8_MININT16_MININT32_MININT64_MIN	minimum value of an object of type int8_t, int16_t, int32_t, int64_t (macro constant)
INT_FAST8_MININT_FAST16_MININT_FAST32_MININT_FAST64_MIN	minimum value of an object of type int_fast8_t, int_fast16_t, int_fast32_t, int_fast64_t (macro constant)
INT_LEAST8_MININT_LEAST16_MININT_LEAST32_MININT_LEAST64_MIN	minimum value of an object of type int_least8_t, int_least16_t, int_least32_t, int_least64_t (macro constant)
INTPTR_MIN	minimum value of an object of type intptr_t (macro constant)
INTMAX_MIN	minimum value of an object of type intmax_t (macro constant)
Signed integers : maximum value
INT8_MAXINT16_MAXINT32_MAXINT64_MAX	maximum value of an object of type int8_t, int16_t, int32_t, int64_t (macro constant)
INT_FAST8_MAXINT_FAST16_MAXINT_FAST32_MAXINT_FAST64_MAX	maximum value of an object of type int_fast8_t, int_fast16_t, int_fast32_t, int_fast64_t (macro constant)
INT_LEAST8_MAXINT_LEAST16_MAXINT_LEAST32_MAXINT_LEAST64_MAX	maximum value of an object of type int_least8_t, int_least16_t, int_least32_t, int_least64_t (macro constant)
INTPTR_MAX	maximum value of an object of type intptr_t (macro constant)
INTMAX_MAX	maximum value of an object of type intmax_t (macro constant)
Unsigned integers : maximum value
UINT8_MAXUINT16_MAXUINT32_MAXUINT64_MAX	maximum value of an object of type uint8_t, uint16_t, uint32_t, uint64_t (macro constant)
UINT_FAST8_MAXUINT_FAST16_MAXUINT_FAST32_MAXUINT_FAST64_MAX	maximum value of an object of type uint_fast8_t, uint_fast16_t, uint_fast32_t, uint_fast64_t (macro constant)
UINT_LEAST8_MAXUINT_LEAST16_MAXUINT_LEAST32_MAXUINT_LEAST64_MAX	maximum value of an object of type uint_least8_t, uint_least16_t, uint_least32_t, uint_least64_t (macro constant)
UINTPTR_MAX	maximum value of an object of type uintptr_t (macro constant)
UINTMAX_MAX	maximum value of an object of type uintmax_t (macro constant)

Function macros for minimum-width integer constants

INT8_CINT16_CINT32_CINT64_C	expands to an integer constant expression having the value specified by its argument and the type int_least8_t, int_least16_t, int_least32_t, int_least64_t respectively (function macro)
INTMAX_C	expands to an integer constant expression having the value specified by its argument and the type intmax_t (function macro)
UINT8_CUINT16_CUINT32_CUINT64_C	expands to an integer constant expression having the value specified by its argument and the type uint_least8_t, uint_least16_t, uint_least32_t, uint_least64_t respectively (function macro)
UINTMAX_C	expands to an integer constant expression having the value specified by its argument and the type uintmax_t (function macro)

#include <cstdint>
UINT64_C(0x123) // expands to a literal of type uint64_t and value 0x123

Format macro constants

Defined in header <cinttypes>

Format constants for the std::fprintf family of functions

Equivalent for int or unsigned int	Description	Macros for data types
		std::intx_t	std::int_leastx_t	std::int_fastx_t	std::intmax_t	std::intptr_t
		x = 8, 16, 32 or 64
d	output of a signed decimal integer value	PRIdx	PRIdLEASTx	PRIdFASTx	PRIdMAX	PRIdPTR
i		PRIix	PRIiLEASTx	PRIiFASTx	PRIiMAX	PRIiPTR
u	output of an unsigned decimal integer value	PRIux	PRIuLEASTx	PRIuFASTx	PRIuMAX	PRIuPTR
o	output of an unsigned octal integer value	PRIox	PRIoLEASTx	PRIoFASTx	PRIoMAX	PRIoPTR
x	output of an unsigned lowercase hexadecimal integer value	PRIxx	PRIxLEASTx	PRIxFASTx	PRIxMAX	PRIxPTR
X	output of an unsigned uppercase hexadecimal integer value	PRIXx	PRIXLEASTx	PRIXFASTx	PRIXMAX	PRIXPTR

Format constants for the std::fscanf family of functions

Equivalent for int or unsigned int	Description	Macros for data types
		std::intx_t	std::int_leastx_t	std::int_fastx_t	std::intmax_t	std::intptr_t
		x = 8, 16, 32 or 64
d	input of a signed decimal integer value	SCNdx	SCNdLEASTx	SCNdFASTx	SCNdMAX	SCNdPTR
i	input of a signed integer value	SCNix	SCNiLEASTx	SCNiFASTx	SCNiMAX	SCNiPTR
u	input of an unsigned decimal integer value	SCNux	SCNuLEASTx	SCNuFASTx	SCNuMAX	SCNuPTR
o	input of an unsigned octal integer value	SCNox	SCNoLEASTx	SCNoFASTx	SCNoMAX	SCNoPTR
x	input of an unsigned hexadecimal integer value	SCNxx	SCNxLEASTx	SCNxFASTx	SCNxMAX	SCNxPTR

Notes

Because C++ interprets a character immediately following a string literal as a user-defined string literal, C code such as printf("%"PRId64"\n",n); is invalid C++ and requires a space before PRId64.

The C99 standard suggests that C++ implementations should not define the above limit, constant, or format macros unless the macros __STDC_LIMIT_MACROS, __STDC_CONSTANT_MACROS or __STDC_FORMAT_MACROS (respectively) are defined before including the relevant C header (stdint.h or inttypes.h). This recommendation was not adopted by any C++ standard and was removed in C11. However, some implementations (such as glibc 2.17) try to apply this rule, and it may be necessary to define the __STDC macros; C++ compilers may try to work around this by automatically defining them in some circumstances.

Example

Run this code

#include <cstdio>
#include <cinttypes>
 
int main()
{
    std::printf("%zu\n", sizeof(std::int64_t));
    std::printf("%s\n", PRId64);
    std::printf("%+" PRId64 "\n", INT64_MIN);
    std::printf("%+" PRId64 "\n", INT64_MAX);
 
    std::int64_t n = 7;
    std::printf("%+" PRId64 "\n", n);
}

Possible output:

8
lld
-9223372036854775808
+9223372036854775807
+7

See also

• Fundamental types

C documentation for Fixed width integer types