diff options
Diffstat (limited to 'doc/info')
| -rw-r--r-- | doc/info/chap/integer-types.texinfo | 248 |
1 files changed, 247 insertions, 1 deletions
diff --git a/doc/info/chap/integer-types.texinfo b/doc/info/chap/integer-types.texinfo index 0684d0b..f8bcda8 100644 --- a/doc/info/chap/integer-types.texinfo +++ b/doc/info/chap/integer-types.texinfo @@ -4,6 +4,7 @@ @menu * Builtin integer types:: Integer types provided by the compiler. +* Portable integer types:: Integer types provided by the standard library. @end menu @@ -25,6 +26,9 @@ made available by including the header file @table @code @item char @tpindex char +@lvindex CHAR_BIT +@lvindex CHAR_MIN +@lvindex CHAR_MAX The smallest addressable unit of the machine that can contain a basic character set. It is either signed or unsigned, depending @@ -36,6 +40,8 @@ is [@code{CHAR_MIN}, @code{CHAR_MAX}]. @item signed char @tpindex signed char +@lvindex SCHAR_MIN +@lvindex SCHAR_MAX @iftex Signed version of @code{char}. It is guaranteed to have a range of either @@ -56,6 +62,8 @@ The exact range is [@code{SCHAR_MIN}, @code{SCHAR_MAX}]. @item unsigned char @tpindex unsigned char +@lvindex UCHAR_MIN +@lvindex UCHAR_MAX @iftex Unsigned version of @code{char}. It is guaranteed to have a range of exactly @@ -75,13 +83,16 @@ or equivalently [0, @code{UCHAR_MAX}]. @itemx signed short @tpindex short int @tpindex signed short int +@lvindex SHORT_MIN +@lvindex SHORT_MAX Signed integer type of at least 16 bits. Its range is guaranteed contain at least [@math{-32767}, @math{32767}]. The exact range [@code{SHORT_MIN}, @code{SHORT_MAX}]. -@itemx unsigned short int +@item unsigned short int @itemx unsigned short @tpindex unsigned short int +@lvindex USHORT_MAX Unsigned integer type of at least 16 bits. Its range is guaranteed contain at least [0, @math{65535}]. The exact range [0, @code{USHORT_MAX}]. @@ -90,12 +101,15 @@ The exact range [0, @code{USHORT_MAX}]. @itemx int @tpindex int @tpindex signed int +@lvindex INT_MIN +@lvindex INT_MAX Signed integer type of at least 16 bits. Its range is guaranteed contain at least [@math{-32767}, @math{32767}]. The exact range [@code{INT_MIN}, @code{INT_MAX}]. @item unsigned int @tpindex unsigned int +@lvindex UINT_MAX Unsigned integer type of at least 16 bits. Its range is guaranteed contain at least [0, @math{65535}]. The exact range [0, @code{UINT_MAX}]. @@ -121,6 +135,8 @@ outside that range [[0, @math{65535}]] should not be used. @itemx signed long @tpindex signed long int @tpindex long int +@lvindex LONG_MIN +@lvindex LONG_MAX Signed integer type of at least 32 bits. Its range is guaranteed contain at least [@math{-2147483647}, @math{2147483647}]. The exact range [@code{LONG_MIN}, @@ -129,6 +145,7 @@ guaranteed contain at least [@math{-2147483647}, @item unsigned long int @itemx unsigned long @tpindex unsigned long int +@lvindex ULONG_MAX Unsigned integer type of at least 32 bits. Its range is guaranteed contain at least [0, @math{4294967295}]. The exact range [0, @code{ULONG_MAX}]. @@ -139,6 +156,8 @@ The exact range [0, @code{ULONG_MAX}]. @itemx signed long long @tpindex long long int @tpindex signed long long int +@lvindex LLONG_MIN +@lvindex LLONG_MAX Signed integer type of at least 64 bits. Its range is guaranteed contain at least [@math{-9223372036854775807}, @math{9223372036854775807}]. This type was added in C99. @@ -147,9 +166,236 @@ The exact range [@code{LLONG_MIN}, @code{LLONG_MAX}]. @item unsigned long long int @itemx unsigned long long @tpindex unsigned long long int +@lvindex ULLONG_MAX Unsigned integer type of at least 64 bits. Its range is guaranteed contain at least [0, @math{18446744073709551615}]. This type was added in C99. The exact range [0, @code{ULLONG_MAX}]. @end table + + +@node Portable integer types +@section Portable integer types + +@cpindex Integer types +@cpindex Types, integer +@hfindex stdint.h +@hfindex inttypes.h +@sc{ISO}@tie{}C99 added integers types of increased +portability. These, and constants describing their +properties, are made available by including either +of the header files @file{<stdint.h>} or +@file{<inttypes.h>}. @file{<inttypes.h>} includes +@file{<stdint.h>}. All integer types have limited +portability, but they --- with exceptions --- +are available even if @code{_PORTABLE_SOURCE} or +@code{_LIBRARY_HEADER} is defined. + +@table @code +@item int@i{N}_t +@tpindex int@i{N}_t +@lvindex INT@i{N}_MIN +@lvindex INT@i{N}_MAX +Signed integer types of exaclty @i{N} bits. +They have do not have any padding bits, and +use two's complement. They are only defined +if there are matching integer types. Thus, +if the compile do not use two's complement, +none will defined. + +Their range are [@code{INT@i{N}_MIN}, +@code{INT@i{N}_MAX}], where +@code{INT@i{N}_MIN == -@code{INT@i{N}_MAX} - 1}, +and @code{INT@i{N}_MAX == (1 << (@i{N} - 1)) - 1}. +Numerical literals, without type suffixes, can +be @sc{CPP}-safely casted to their type with +the macros @code{INT@i{N}_C(value)}. + +@code{int@i{N}_t}, where @i{N} is 8, 16, 32, +or 64, must be defined if possible. + +These types are standard library-independent, +but compiler-dependent and machine-dependent. + +@item uint@i{N}_t +@tpindex uint@i{N}_t +@lvindex UINT@i{N}_MAX +Unsigned integer types of exaclty @i{N} bits. +They have do not have any padding bits. They +are only defined if there are matching integer +types. + +Their range are [0, @code{UINT@i{N}_MAX}], where +@code{UINT@i{N}_MAX == (1 << @i{N}) - 1}. +Numerical literals, without type suffixes, can +be @sc{CPP}-safely casted to their type with +the macros @code{UINT@i{N}_C(value)}. + +@code{int@i{N}_t}, where @i{N} is 8, 16, 32, +or 64, must be defined if possible. + +These types are standard library-independent +and compiler-independent, but machine-dependent. + +@item int_least@i{N}_t +@tpindex int_least@i{N}_t +@lvindex INT_LEAST@i{N}_MIN +@lvindex INT_LEAST@i{N}_MAX +Signed integer types with ranges of at least +[@code{INT@i{N}_MIN}, @code{INT@i{N}_MAX}]. +The types are as narrow as possible, they +do not however need to use two's complement. +Numerical literals, without type suffixes, can +be @sc{CPP}-safely casted to their type with +the macros @code{INT_LEAST@i{N}_C(value)}. + +Types where @i{N} is 8, 16, 32, or 64 are +guaranteed to be defined. + +These types are standard library-independent, +but compiler-dependent and machine-dependent. + +The exact ranges of these types are +[@code{INT_LEAST@i{N}_MIN}, @code{INT_LEAST@i{N}_MAX}]. + +@item uint_least@i{N}_t +@tpindex uint_least@i{N}_t +@lvindex UINT_LEAST@i{N}_MAX +Unsigned integer types with ranges of at least +[0, @code{UINT@i{N}_MAX}]. The types are +as narrow as possible. Numerical literals, +without type suffixes, can be @sc{CPP}-safely +casted to their type with the macros +@code{UINT_LEAST@i{N}_C(value)}. + +Types where @i{N} is 8, 16, 32, or 64 are +guaranteed to be defined. + +These types are standard library-independent +and compiler-independent, but machine-dependent. + +The exact ranges of these types are +[0, @code{UINT_LEAST@i{N}_MAX}]. + +@item int_fast@i{N}_t +@tpindex int_fast@i{N}_t +@lvindex INT_FAST@i{N}_MIN +@lvindex INT_FAST@i{N}_MAX +Signed integer types with ranges of at least +[@code{INT@i{N}_MIN}, @code{INT@i{N}_MAX}]. +They do not need to use two's complement. +Numerical literals, without type suffixes, can +be @sc{CPP}-safely casted to their type with +the macros @code{INT_FAST@i{N}_C(value)}. + +Types where @i{N} is 8, 16, 32, or 64 are +guaranteed to be defined. + +The underlaying types of these types are selected, +by the C standard library, to the types that +are thought to be the fastest type to operate +over in most use-cases. +For example, @code{int_fast16_t} can actually +be a @code{int64_t} (@code{long long int}). + +These types are standard library-dependent, +compiler-dependent and machine-dependent. + +The exact ranges of these types are +[@code{INT_FAST@i{N}_MIN}, @code{INT_FAST@i{N}_MAX}]. + +@item uint_fast@i{N}_t +@tpindex uint_fast@i{N}_t +@lvindex UINT_FAST@i{N}_MAX +Signed integer types with ranges of at least +[0, @code{UINT@i{N}_MAX}]. Numerical literals, +without type suffixes, can be @sc{CPP}-safely +casted to their type with the macros +@code{UINT_FAST@i{N}_C(value)}. + +Types where @i{N} is 8, 16, 32, or 64 are +guaranteed to be defined. + +The underlaying types of these types are selected, +by the C standard library, to the types that +are thought to be the fastest type to operate +over in most use-cases. +For example, @code{uint_fast16_t} can actually +be a @code{uint64_t} (@code{unsigned long long int}). + +These types are standard library-dependent and +machine-dependent, but compiler-independent. + +The exact ranges of these types are +[0, @code{UINT_FAST@i{N}_MAX}]. + +@item intmax_t +@tpindex intmax_t +@lvindex INTMAX_MIN +@lvindex INTMAX_MAX +Widest natively available signed integer type. +If the compiler provides wider integers than the +machine, the widest integer provided by the machine +(not the compiler) is used. + +Because @code{long long int} has at least 64 bits, +this type has at least 64 bits too. + +This type is standard library-independent and +compiler-independent, but machine-dependent. + +The range if this type is [@code{INTMAX_MIN}, +@code{INTMAX_MAX}]. + +@item uintmax_t +@tpindex uintmax_t +@lvindex UINTMAX_MAX +Widest natively available unsigned integer type. +If the compiler provides wider integers than the +machine, the widest integer provided by the machine +(not the compiler) is used. + +Because @code{long long int} has at least 64 bits, +this type has at least 64 bits too. + +This type is standard library-independent and +compiler-independent, but machine-dependent. + +The range if this type is [0, @code{UINTMAX_MAX}]. + +@item intptr_t +@tpindex intptr_t +@lvindex INTPTR_MIN +@lvindex INTPTR_MAX +Signed integer type cast to or from +@code{void*} without loss of precision. It can +point to any address. + +This type is standard library-independent and +compiler-independent, but machine-dependent. + +The range if this type is [@code{INTPTR_MIN}, +@code{INTMAX_MAX}]. + +@item uintptr_t +@tpindex uintptr_t +@lvindex UINTPTR_MAX +Unsigned integer type cast to or from +@code{void*} without loss of precision. It can +point to any address. + +This type is standard library-independent and +compiler-independent, but machine-dependent. + +The range if this type is [0, @code{UINTPTR_MAX}]. + +@end table + +Types where @i{N} is neither 8, 16, 32, nor 64, +are not available if @code{_PORTABLE_SOURCE} or +@code{_LIBRARY_HEADER} is defined. @command{slibc}, +currently, does not define any integer types where +@i{N} is neither 8, 16, 32, nor 64. + + |