2014-06-01 02:52:39 -07:00
< html >
< head >
2020-06-23 18:55:52 +01:00
< meta http-equiv = "Content-Type" content = "text/html; charset=UTF-8" >
2014-06-01 02:52:39 -07:00
< title > Standard Integer Types< / title >
< link rel = "stylesheet" href = "../../../../../doc/src/boostbook.css" type = "text/css" >
2018-08-03 13:09:53 +01:00
< meta name = "generator" content = "DocBook XSL Stylesheets V1.79.1" >
2014-06-01 02:52:39 -07:00
< link rel = "home" href = "../index.html" title = "Boost.Config" >
< link rel = "up" href = "../index.html" title = "Boost.Config" >
2014-06-12 13:30:04 +01:00
< link rel = "prev" href = "build_config.html" title = "Build Time Configuration" >
2014-06-01 02:52:39 -07:00
< link rel = "next" href = "guidelines_for_boost_authors.html" title = "Guidelines for Boost Authors" >
2023-09-10 10:32:26 +01:00
< meta name = "viewport" content = "width=device-width, initial-scale=1" >
2014-06-01 02:52:39 -07:00
< / head >
< body bgcolor = "white" text = "black" link = "#0000FF" vlink = "#840084" alink = "#0000FF" >
< table cellpadding = "2" width = "100%" > < tr >
< td valign = "top" > < img alt = "Boost C++ Libraries" width = "277" height = "86" src = "../../../../../boost.png" > < / td >
< td align = "center" > < a href = "../../../../../index.html" > Home< / a > < / td >
< td align = "center" > < a href = "../../../../../libs/libraries.htm" > Libraries< / a > < / td >
< td align = "center" > < a href = "http://www.boost.org/users/people.html" > People< / a > < / td >
< td align = "center" > < a href = "http://www.boost.org/users/faq.html" > FAQ< / a > < / td >
< td align = "center" > < a href = "../../../../../more/index.htm" > More< / a > < / td >
< / tr > < / table >
< hr >
< div class = "spirit-nav" >
2014-06-12 13:30:04 +01:00
< a accesskey = "p" href = "build_config.html" > < img src = "../../../../../doc/src/images/prev.png" alt = "Prev" > < / a > < a accesskey = "u" href = "../index.html" > < img src = "../../../../../doc/src/images/up.png" alt = "Up" > < / a > < a accesskey = "h" href = "../index.html" > < img src = "../../../../../doc/src/images/home.png" alt = "Home" > < / a > < a accesskey = "n" href = "guidelines_for_boost_authors.html" > < img src = "../../../../../doc/src/images/next.png" alt = "Next" > < / a >
2014-06-01 02:52:39 -07:00
< / div >
< div class = "section" >
< div class = "titlepage" > < div > < div > < h2 class = "title" style = "clear: both" >
< a name = "boost_config.cstdint" > < / a > < a class = "link" href = "cstdint.html" title = "Standard Integer Types" > Standard Integer Types< / a >
< / h2 > < / div > < / div > < / div >
2018-08-03 13:09:53 +01:00
< div class = "toc" > < dl class = "toc" >
2014-06-01 02:52:39 -07:00
< dt > < span class = "section" > < a href = "cstdint.html#boost_config.cstdint.overview" > Overview< / a > < / span > < / dt >
< dt > < span class = "section" > < a href = "cstdint.html#boost_config.cstdint.rationale" > Rationale< / a > < / span > < / dt >
< dt > < span class = "section" > < a href = "cstdint.html#boost_config.cstdint.ce" > < span class = "emphasis" > < em > Caveat emptor< / em > < / span > < / a > < / span > < / dt >
< dt > < span class = "section" > < a href = "cstdint.html#boost_config.cstdint.exact_width_integer_types" > Exact-width
integer types< / a > < / span > < / dt >
< dt > < span class = "section" > < a href = "cstdint.html#boost_config.cstdint.minimum_width_integer_types" > Minimum-width
integer types< / a > < / span > < / dt >
< dt > < span class = "section" > < a href = "cstdint.html#boost_config.cstdint.fastest_minimum_width_integer_types" > Fastest
minimum-width integer types< / a > < / span > < / dt >
< dt > < span class = "section" > < a href = "cstdint.html#boost_config.cstdint.greatest_width_integer_types" > Greatest-width
integer types< / a > < / span > < / dt >
< dt > < span class = "section" > < a href = "cstdint.html#boost_config.cstdint.integer_constant_macros" > Integer
Constant Macros< / a > < / span > < / dt >
2018-08-03 13:09:53 +01:00
< dt > < span class = "section" > < a href = "cstdint.html#boost_config.cstdint.intptr" > Integers for Storing Pointers< / a > < / span > < / dt >
2014-06-01 02:52:39 -07:00
< / dl > < / div >
< div class = "section" >
< div class = "titlepage" > < div > < div > < h3 class = "title" >
< a name = "boost_config.cstdint.overview" > < / a > < a class = "link" href = "cstdint.html#boost_config.cstdint.overview" title = "Overview" > Overview< / a >
< / h3 > < / div > < / div > < / div >
< p >
The header < code class = "literal" > < a href = "../../../../../boost/cstdint.hpp" target = "_top" > < boost/cstdint.hpp> < / a > < / code >
provides the typedef's useful for writing portable code that requires certain
integer widths. All typedef's are in namespace boost.
< / p >
< p >
The specifications for these types are based on the ISO/IEC 9899:1999 C Language
standard header < stdint.h> . The 64-bit types required by the C standard
are < span class = "emphasis" > < em > not required< / em > < / span > in the boost header, and may not be
supplied for all platforms/compilers, because < code class = "literal" > long long< / code >
is not [yet] included in the C++ standard.
< / p >
< p >
See < a href = "../../../test/cstdint_test.cpp" target = "_top" > cstdint_test.cpp< / a > for
a test program.
< / p >
< / div >
< div class = "section" >
< div class = "titlepage" > < div > < div > < h3 class = "title" >
< a name = "boost_config.cstdint.rationale" > < / a > < a class = "link" href = "cstdint.html#boost_config.cstdint.rationale" title = "Rationale" > Rationale< / a >
< / h3 > < / div > < / div > < / div >
< p >
The organization of the Boost.Integer headers and classes is designed to
take advantage of < stdint.h> types from the 1999 C standard without
causing undefined behavior in terms of the 1998 C++ standard. The header
< boost/cstdint.hpp> makes the standard integer types safely available
in namespace < code class = "literal" > boost< / code > without placing any names in namespace
< code class = "literal" > std< / code > . The intension is to complement rather than compete
with the C++ Standard Library. Should some future C++ standard include < stdint.h>
and < cstdint> , then < boost/cstdint.hpp> will continue to function,
but will become redundant and may be safely deprecated.
< / p >
< p >
Because these are boost headers, their names conform to boost header naming
conventions rather than C++ Standard Library header naming conventions.
< / p >
< / div >
< div class = "section" >
< div class = "titlepage" > < div > < div > < h3 class = "title" >
< a name = "boost_config.cstdint.ce" > < / a > < a class = "link" href = "cstdint.html#boost_config.cstdint.ce" title = "Caveat emptor" > < span class = "emphasis" > < em > Caveat emptor< / em > < / span > < / a >
< / h3 > < / div > < / div > < / div >
< p >
As an implementation artifact, certain C < limits.h> macro names may
possibly be visible to users of < boost/cstdint.hpp> . Don't use these
macros; they are not part of any Boost-specified interface. Use < code class = "literal" > boost::integer_traits< > < / code >
or < code class = "literal" > std::numeric_limits< > < / code > instead.
< / p >
< p >
As another implementation artifact, certain C < stdint.h> typedef names
may possibly be visible in the global namespace to users of < boost/cstdint.hpp> .
Don't use these names, they are not part of any Boost-specified interface.
Use the respective names in namespace < code class = "literal" > boost< / code > instead.
< / p >
< / div >
< div class = "section" >
< div class = "titlepage" > < div > < div > < h3 class = "title" >
< a name = "boost_config.cstdint.exact_width_integer_types" > < / a > < a class = "link" href = "cstdint.html#boost_config.cstdint.exact_width_integer_types" title = "Exact-width integer types" > Exact-width
integer types< / a >
< / h3 > < / div > < / div > < / div >
< p >
The typedef < code class = "literal" > int#_t< / code > , with # replaced by the width, designates
a signed integer type of exactly # bits; for example < code class = "literal" > int8_t< / code >
denotes an 8-bit signed integer type. Similarly, the typedef < code class = "literal" > uint#_t< / code >
designates an unsigned integer type of exactly # bits.
< / p >
< p >
These types are optional. However, if a platform supports integer types with
widths of 8, 16, 32, 64, or any combination thereof, then < boost/cstdint.hpp>
does provide the corresponding typedefs.
< / p >
< p >
The absence of int64_t and uint64_t is indicated by the macro < code class = "computeroutput" > < span class = "identifier" > BOOST_NO_INT64_T< / span > < / code > .
< / p >
< / div >
< div class = "section" >
< div class = "titlepage" > < div > < div > < h3 class = "title" >
< a name = "boost_config.cstdint.minimum_width_integer_types" > < / a > < a class = "link" href = "cstdint.html#boost_config.cstdint.minimum_width_integer_types" title = "Minimum-width integer types" > Minimum-width
integer types< / a >
< / h3 > < / div > < / div > < / div >
< p >
The typedef < code class = "literal" > int_least#_t< / code > , with # replaced by the width,
designates a signed integer type with a width of at least # bits, such that
no signed integer type with lesser size has at least the specified width.
Thus, < code class = "literal" > int_least32_t< / code > denotes the smallest signed integer
type with a width of at least 32 bits. Similarly, the typedef name < code class = "literal" > uint_least#_t< / code >
designates an unsigned integer type with a width of at least # bits, such
that no unsigned integer type with lesser size has at least the specified
width.
< / p >
< p >
The following minimum-width integer types are provided for all platforms:
< / p >
< div class = "itemizedlist" > < ul class = "itemizedlist" style = "list-style-type: disc; " >
< li class = "listitem" >
< code class = "literal" > int_least8_t< / code >
< / li >
< li class = "listitem" >
< code class = "literal" > int_least16_t< / code >
< / li >
< li class = "listitem" >
< code class = "literal" > int_least32_t< / code >
< / li >
< li class = "listitem" >
< code class = "literal" > uint_least8_t< / code >
< / li >
< li class = "listitem" >
< code class = "literal" > uint_least16_t< / code >
< / li >
< li class = "listitem" >
< code class = "literal" > uint_least32_t< / code >
< / li >
< / ul > < / div >
< p >
The following types are available only if, after including < boost/cstdint.hpp> ,
the macro BOOST_NO_INT64_T is not defined:
< / p >
< div class = "itemizedlist" > < ul class = "itemizedlist" style = "list-style-type: disc; " >
< li class = "listitem" >
< code class = "literal" > int_least64_t< / code >
< / li >
< li class = "listitem" >
< code class = "literal" > uint_least64_t< / code >
< / li >
< / ul > < / div >
< p >
All other minimum-width integer types are optional.
< / p >
< / div >
< div class = "section" >
< div class = "titlepage" > < div > < div > < h3 class = "title" >
< a name = "boost_config.cstdint.fastest_minimum_width_integer_types" > < / a > < a class = "link" href = "cstdint.html#boost_config.cstdint.fastest_minimum_width_integer_types" title = "Fastest minimum-width integer types" > Fastest
minimum-width integer types< / a >
< / h3 > < / div > < / div > < / div >
< p >
The typedef < code class = "literal" > int_fast#_t< / code > , with # replaced by the width,
designates the fastest signed integer type with a width of at least # bits.
Similarly, the typedef name < code class = "literal" > uint_fast#_t< / code > designates the
fastest unsigned integer type with a width of at least # bits.
< / p >
< p >
There is no guarantee that these types are fastest for all purposes. In any
case, however, they satisfy the signedness and width requirements.
< / p >
< p >
The following fastest minimum-width integer types are provided for all platforms:
< / p >
< div class = "itemizedlist" > < ul class = "itemizedlist" style = "list-style-type: disc; " >
< li class = "listitem" >
< code class = "literal" > int_fast8_t< / code >
< / li >
< li class = "listitem" >
< code class = "literal" > int_fast16_t< / code >
< / li >
< li class = "listitem" >
< code class = "literal" > int_fast32_t< / code >
< / li >
< li class = "listitem" >
< code class = "literal" > uint_fast8_t< / code >
< / li >
< li class = "listitem" >
< code class = "literal" > uint_fast16_t< / code >
< / li >
< li class = "listitem" >
< code class = "literal" > uint_fast32_t< / code >
< / li >
< / ul > < / div >
< p >
The following types are available only if, after including < boost/cstdint.hpp> ,
the macro BOOST_NO_INT64_T is not defined:
< / p >
< div class = "itemizedlist" > < ul class = "itemizedlist" style = "list-style-type: disc; " >
< li class = "listitem" >
< code class = "literal" > int_fast64_t< / code >
< / li >
< li class = "listitem" >
< code class = "literal" > uint_fast64_t< / code >
< / li >
< / ul > < / div >
< p >
All other fastest minimum-width integer types are optional.
< / p >
< / div >
< div class = "section" >
< div class = "titlepage" > < div > < div > < h3 class = "title" >
< a name = "boost_config.cstdint.greatest_width_integer_types" > < / a > < a class = "link" href = "cstdint.html#boost_config.cstdint.greatest_width_integer_types" title = "Greatest-width integer types" > Greatest-width
integer types< / a >
< / h3 > < / div > < / div > < / div >
< p >
The typedef < code class = "literal" > intmax_t < / code > designates a signed integer type
capable of representing any value of any signed integer type.
< / p >
< p >
The typedef < code class = "literal" > uintmax_t< / code > designates an unsigned integer type
capable of representing any value of any unsigned integer type.
< / p >
< p >
These types are provided for all platforms.
< / p >
< / div >
< div class = "section" >
< div class = "titlepage" > < div > < div > < h3 class = "title" >
< a name = "boost_config.cstdint.integer_constant_macros" > < / a > < a class = "link" href = "cstdint.html#boost_config.cstdint.integer_constant_macros" title = "Integer Constant Macros" > Integer
Constant Macros< / a >
< / h3 > < / div > < / div > < / div >
< p >
The following macros are always defined after inclusion of this header, these
allow integer constants of at least the specified width to be declared: INT8_C,
UINT8_C, INT16_C, UINT16_C, INT32_C, UINT32_C, INTMAX_C, UINTMAX_C.
< / p >
< p >
The macros INT64_C and UINT64_C are also defined if the the macro BOOST_NO_INT64_T
is not defined.
< / p >
< p >
The C99 macro __STDC_CONSTANT_MACROS is also defined as an artifact of the
implementation.
< / p >
< p >
For example:
< / p >
< pre class = "programlisting" > < span class = "preprocessor" > #include< / span > < span class = "special" > < < / span > < span class = "identifier" > boost< / span > < span class = "special" > /< / span > < span class = "identifier" > cstdint< / span > < span class = "special" > .< / span > < span class = "identifier" > hpp< / span > < span class = "special" > > < / span >
< span class = "comment" > // Here the constant 0x1FFFFFFFF has the correct suffix applied:< / span >
< span class = "keyword" > static< / span > < span class = "keyword" > const< / span > < span class = "identifier" > boost< / span > < span class = "special" > ::< / span > < span class = "identifier" > uint64_t< / span > < span class = "identifier" > c< / span > < span class = "special" > =< / span > < span class = "identifier" > INT64_C< / span > < span class = "special" > (< / span > < span class = "number" > 0< / span > < span class = "identifier" > x1FFFFFFFF< / span > < span class = "special" > );< / span >
< / pre >
< / div >
2018-08-03 13:09:53 +01:00
< div class = "section" >
< div class = "titlepage" > < div > < div > < h3 class = "title" >
< a name = "boost_config.cstdint.intptr" > < / a > < a class = "link" href = "cstdint.html#boost_config.cstdint.intptr" title = "Integers for Storing Pointers" > Integers for Storing Pointers< / a >
< / h3 > < / div > < / div > < / div >
< p >
The typedefs < code class = "literal" > intptr_t< / code > and < code class = "literal" > uintptr_t< / code >
defined signed and unsigned integers respectively each capable of storing
a pointer. The macro < code class = "literal" > BOOST_HAS_INTPTR_T< / code > is set when these
types are available.
< / p >
< / div >
2014-06-01 02:52:39 -07:00
< / div >
2023-09-10 10:32:26 +01:00
< div class = "copyright-footer" > Copyright © 2001-2007 Beman Dawes, Vesa Karvonen, John
2014-06-01 02:52:39 -07:00
Maddock< p >
Distributed under the Boost Software License, Version 1.0. (See accompanying
file LICENSE_1_0.txt or copy at < a href = "http://www.boost.org/LICENSE_1_0.txt" target = "_top" > http://www.boost.org/LICENSE_1_0.txt< / a > )
< / p >
2023-09-10 10:32:26 +01:00
< / div >
2014-06-01 02:52:39 -07:00
< hr >
< div class = "spirit-nav" >
2014-06-12 13:30:04 +01:00
< a accesskey = "p" href = "build_config.html" > < img src = "../../../../../doc/src/images/prev.png" alt = "Prev" > < / a > < a accesskey = "u" href = "../index.html" > < img src = "../../../../../doc/src/images/up.png" alt = "Up" > < / a > < a accesskey = "h" href = "../index.html" > < img src = "../../../../../doc/src/images/home.png" alt = "Home" > < / a > < a accesskey = "n" href = "guidelines_for_boost_authors.html" > < img src = "../../../../../doc/src/images/next.png" alt = "Next" > < / a >
2014-06-01 02:52:39 -07:00
< / div >
< / body >
< / html >
