xref: /freebsd/share/man/man7/stdint.7 (revision 41059135ce931c0f1014a999ffabc6bc470ce856)
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25.\" $FreeBSD$
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27.Dd September 15, 2002
28.Dt STDINT 7
29.Os
30.Sh NAME
31.Nm stdint
32.Nd "standard integer types"
33.Sh SYNOPSIS
34.In stdint.h
35.Sh DESCRIPTION
36The
37.In stdint.h
38header provides source-portable integer types of a specific
39size, smallest memory footprint with a minimum size, fastest
40access speed with a minimum size, largest integer size, and
41those capable of storing pointers.
42.Pp
43The types
44.Vt int8_t ,
45.Vt int16_t ,
46.Vt int32_t ,
47and
48.Vt int64_t
49provide a signed integer type of width 8, 16, 32, or 64 bits, respectively.
50The types
51.Vt uint8_t ,
52.Vt uint16_t ,
53.Vt uint32_t ,
54and
55.Vt uint64_t
56provide an unsigned integer type of width 8, 16, 32, or 64 bits, respectively.
57These integer types should be used when a specific size is required.
58.Pp
59The types
60.Vt int_fast8_t ,
61.Vt int_fast16_t ,
62.Vt int_fast32_t ,
63and
64.Vt int_fast64_t
65provide the fastest signed integer type with a width
66of at least 8, 16, 32, or 64 bits, respectively.
67The types
68.Vt uint_fast8_t ,
69.Vt uint_fast16_t ,
70.Vt uint_fast32_t ,
71and
72.Vt uint_fast64_t
73provide the fastest unsigned integer type with a width
74of at least 8, 16, 32, or 64 bits, respectively.
75These types should be used when access speed is
76paramount, and when a specific size is not required.
77.Pp
78The types
79.Vt int_least8_t ,
80.Vt int_least16_t ,
81.Vt int_least32_t ,
82and
83.Vt int_least64_t
84provide the smallest memory footprint signed integer type with
85a width of at least 8, 16, 32, or 64 bits, respectively.
86The types
87.Vt uint_least8_t ,
88.Vt uint_least16_t ,
89.Vt uint_least32_t ,
90and
91.Vt uint_least64_t
92provide the smallest memory footprint unsigned integer type with
93a width of at least 8, 16, 32, or 64 bits, respectively.
94These types should be used when memory storage is of
95concern, and when a specific size is not required.
96.Pp
97The type
98.Vt intmax_t
99provides a signed integer type large
100enough to hold any other signed integer.
101The type
102.Vt uintmax_t
103provides an unsigned integer type large
104enough to hold any other unsigned integer.
105These types are generally the largest signed and unsigned
106integer types available on a specific architecture.
107.Pp
108The type
109.Vt intptr_t
110provides a signed integer type with the ability to hold a pointer to
111.Vt void ,
112that can later be converted back to a pointer to
113.Vt void .
114.Pp
115The type
116.Vt uintptr_t
117provides an unsigned integer type with the ability to hold a pointer to
118.Vt void ,
119that can later be converted back to a pointer to
120.Vt void .
121.Pp
122Additionally, the
123.In stdint.h
124header defines some macros, but none of them are documented here.
125.Sh STANDARDS
126The
127.In stdint.h
128header conforms to
129.St -isoC-99
130and
131.St -p1003.1-2001 .
132.Sh HISTORY
133The
134.In stdint.h
135header was first introduced in
136.Fx 5.0 .
137