The header <boost/cstdint.hpp> provides the typedef's useful for writing portable code that requires certain integer widths. All typedef's are in namespace boost.

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 not required in the boost header, and may not be supplied for all platforms/compilers, because long long is not [yet] included in the C++ standard.

See cstdint_test.cpp for a test program.

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 boost without placing any names in namespace std. 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.

Because these are boost headers, their names conform to boost header naming conventions rather than C++ Standard Library header naming conventions.

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 boost::integer_traits<> or std::numeric_limits<> instead.

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 boost instead.

The typedef int#_t, with # replaced by the width, designates a signed integer type of exactly # bits; for example int8_t denotes an 8-bit signed integer type. Similarly, the typedef uint#_t designates an unsigned integer type of exactly # bits.

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.

The absence of int64_t and uint64_t is indicated by the macro BOOST_NO_INT64_T.

The typedef int_least#_t, 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, int_least32_t denotes the smallest signed integer type with a width of at least 32 bits. Similarly, the typedef name uint_least#_t 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.

The following minimum-width integer types are provided for all platforms:

The following types are available only if, after including <boost/cstdint.hpp>, the macro BOOST_NO_INT64_T is not defined:

All other minimum-width integer types are optional.

The typedef int_fast#_t, with # replaced by the width, designates the fastest signed integer type with a width of at least # bits. Similarly, the typedef name uint_fast#_t designates the fastest unsigned integer type with a width of at least # bits.

There is no guarantee that these types are fastest for all purposes. In any case, however, they satisfy the signedness and width requirements.

The following fastest minimum-width integer types are provided for all platforms:

The following types are available only if, after including <boost/cstdint.hpp>, the macro BOOST_NO_INT64_T is not defined:

All other fastest minimum-width integer types are optional.

The typedef intmax_t designates a signed integer type capable of representing any value of any signed integer type.

The typedef uintmax_t designates an unsigned integer type capable of representing any value of any unsigned integer type.

These types are provided for all platforms.