xref: /freebsd/share/man/man7/stdint.7 (revision 4f8f43b06ed07e96a250855488cc531799d5b78f)
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25.Dd September 15, 2002
26.Dt STDINT 7
27.Os
28.Sh NAME
29.Nm stdint
30.Nd "standard integer types"
31.Sh SYNOPSIS
32.In stdint.h
33.Sh DESCRIPTION
34The
35.In stdint.h
36header provides source-portable integer types of a specific
37size, smallest memory footprint with a minimum size, fastest
38access speed with a minimum size, largest integer size, and
39those capable of storing pointers.
40.Pp
41The types
42.Vt int8_t ,
43.Vt int16_t ,
44.Vt int32_t ,
45and
46.Vt int64_t
47provide a signed integer type of width 8, 16, 32, or 64 bits, respectively.
48The types
49.Vt uint8_t ,
50.Vt uint16_t ,
51.Vt uint32_t ,
52and
53.Vt uint64_t
54provide an unsigned integer type of width 8, 16, 32, or 64 bits, respectively.
55These integer types should be used when a specific size is required.
56.Pp
57The types
58.Vt int_fast8_t ,
59.Vt int_fast16_t ,
60.Vt int_fast32_t ,
61and
62.Vt int_fast64_t
63provide the fastest signed integer type with a width
64of at least 8, 16, 32, or 64 bits, respectively.
65The types
66.Vt uint_fast8_t ,
67.Vt uint_fast16_t ,
68.Vt uint_fast32_t ,
69and
70.Vt uint_fast64_t
71provide the fastest unsigned integer type with a width
72of at least 8, 16, 32, or 64 bits, respectively.
73These types should be used when access speed is
74paramount, and when a specific size is not required.
75.Pp
76The types
77.Vt int_least8_t ,
78.Vt int_least16_t ,
79.Vt int_least32_t ,
80and
81.Vt int_least64_t
82provide the smallest memory footprint signed integer type with
83a width of at least 8, 16, 32, or 64 bits, respectively.
84The types
85.Vt uint_least8_t ,
86.Vt uint_least16_t ,
87.Vt uint_least32_t ,
88and
89.Vt uint_least64_t
90provide the smallest memory footprint unsigned integer type with
91a width of at least 8, 16, 32, or 64 bits, respectively.
92These types should be used when memory storage is of
93concern, and when a specific size is not required.
94.Pp
95The type
96.Vt intmax_t
97provides a signed integer type large
98enough to hold any other signed integer.
99The type
100.Vt uintmax_t
101provides an unsigned integer type large
102enough to hold any other unsigned integer.
103These types are generally the largest signed and unsigned
104integer types available on a specific architecture.
105.Pp
106The type
107.Vt intptr_t
108provides a signed integer type with the ability to hold a pointer to
109.Vt void ,
110that can later be converted back to a pointer to
111.Vt void .
112.Pp
113The type
114.Vt uintptr_t
115provides an unsigned integer type with the ability to hold a pointer to
116.Vt void ,
117that can later be converted back to a pointer to
118.Vt void .
119.Pp
120Additionally, the
121.In stdint.h
122header defines some macros, but none of them are documented here.
123.Sh STANDARDS
124The
125.In stdint.h
126header conforms to
127.St -isoC-99
128and
129.St -p1003.1-2001 .
130.Sh HISTORY
131The
132.In stdint.h
133header was first introduced in
134.Fx 5.0 .
135