Narrowest integer types of at least 64 bits

Names specified here
Name	Description	Notes				Source
`atomic_int_least64_t`	Atomic integer type		?		T	`<stdatomic.h>`		C11
`atomic_uint_least64_t`	Atomic integer type		?		T	`<stdatomic.h>`		C11
`INT64_C()`	Create constant of type `int_least64_t`	L		M	(·)	`<stdint.h>`	C99	C11
`INT_LEAST64_MAX`	Maximum value of `int_least64_t`	L		M		`<stdint.h>`	C99	C11
`INT_LEAST64_MIN`	Minimum value of `int_least64_t`	L		M		`<stdint.h>`	C99	C11
`int_least64_t`	Smallest signed integer type with at least 64 bits	L			T	`<stdint.h>`	C99	C11
`PRIdLEAST64`	Decimal output conversion specifier for `int_least64_t`			M		`<inttypes.h>`	C99	C11
`PRIiLEAST64`	Decimal output conversion specifier for `int_least64_t`			M		`<inttypes.h>`	C99	C11
`PRIoLEAST64`	Octal output conversion specifier for `uint_least64_t`			M		`<inttypes.h>`	C99	C11
`PRIuLEAST64`	Decimal output conversion specifier for `uint_least64_t`			M		`<inttypes.h>`	C99	C11
`PRIXLEAST64`	Hexdecimal output conversion specifier for `uint_least64_t`			M		`<inttypes.h>`	C99	C11
`PRIxLEAST64`	Hexdecimal output conversion specifier for `uint_least64_t`			M		`<inttypes.h>`	C99	C11
`SCNdLEAST64`	Decimal input conversion specifier for `int_least64_t`			M		`<inttypes.h>`	C99	C11
`SCNiLEAST64`	General input conversion specifier for `int_least64_t`			M		`<inttypes.h>`	C99	C11
`SCNoLEAST64`	Octal input conversion specifier for `uint_least64_t`			M		`<inttypes.h>`	C99	C11
`SCNuLEAST64`	Decimal input conversion specifier for `uint_least64_t`			M		`<inttypes.h>`	C99	C11
`SCNxLEAST64`	Hexdecimal input conversion specifier for `uint_least64_t`			M		`<inttypes.h>`	C99	C11
`UINT64_C()`	Create constant of type `uint_least64_t`	L		M	(·)	`<stdint.h>`	C99	C11
`UINT_LEAST64_MAX`	Maximum value of `uint_least64_t`	L		M		`<stdint.h>`	C99	C11
`uint_least64_t`	Smallest unsigned integer type with at least 64 bits	L			T	`<stdint.h>`	C99	C11

uint_least64_t and int_least64_t are the smallest integer types of at least 64 bits. uint_least64_t is unsigned, and has the range zero to UINT_LEAST64_MAX, which is at least [0, +18446744073709551615]. int_least64_t is signed, and has the range INT_LEAST64_MIN to INT_LEAST64_MAX, which is at least [−9223372036854775807, +9223372036854775807].

The following macros can be used in the fmt argument of printf to print arguments of types uint_least64_t and int_least64_t:

PRIuLEAST64
PRIoLEAST64
PRIxLEAST64
PRIXLEAST64
PRIdLEAST64
PRIiLEAST64

The following macros can be used in the fmt argument of scanf to scan arguments of types uint_least64_t * and int_least64_t *:

SCNuLEAST64
SCNoLEAST64
SCNxLEAST64
SCNdLEAST64
SCNiLEAST64

atomic_uint_least64_t is an alias for _Atomic uint_least64_t. atomic_int_least64_t is an alias for _Atomic int_least64_t.

Related types:

uint64_t
int64_t
uint_least64_t
int_least64_t
uint_fast64_t
int_fast64_t

Property		`uint_least64_t`	`int_least64_t`
Minimum width (bits)		64
Lowest value		0	≤−9223372036854775807
Highest value		≥+18446744073709551615	≥+9223372036854775807
Constant		`UINT64_C(untyped-integer-constant)`	`INT64_C(untyped-integer-constant)`
`printf`	base 10	`"%" PRIuLEAST64`	`"%" PRIdLEAST64` or `"%" PRIiLEAST64`
	base 8	`"%" PRIoLEAST64`
	upper-case base 16	`"%" PRIXLEAST64`
	lower-case base 16	`"%" PRIxLEAST64`
`scanf`	base 10	`"%" SCNuLEAST64`	`"%" SCNdLEAST64`
	base 8	`"%" SCNoLEAST64`
	base 16	`"%" SCNxLEAST64`
	base 16, 8 or 10 by prefix		`"%" SCNiLEAST64`