Standard Types

 

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The Microsoft run-time library defines the following standard types and typedefs.

Fixed-width integral types (stdint.h)

NameEquivalent built-in type
int8_t, uint8_tsigned char, unsigned char
int16_t, int16_tshort, unsigned short
int32_t, uint32_tint, unsigned int
int64_t, int64_tlong long, unsigned long long
int_least8_t, uint_least8_tsigned char, unsigned char
int_least16_t, uint_least16_tshort, unsigned short
int_least32_t, uint_least32_tint, unsigned int
int_least64_t, uint_least64_tlong long, unsigned long long
int_fast8_t, uint_fast8_tsigned char, unsigned char
int_fast16_t, uint_fast16_tint, unsigned int
int_fast32_t, uint_fast32_tint, unsigned int
int_fast64_t, uint_fast64_tlong long, unsigned long long
intmax_t, uintmax_tlong long, unsigned long long
TypeDescriptionDeclared in
clock_t (long)Stores time values; used by clock.TIME.H
_complex structureStores real and imaginary parts of complex numbers; used by _cabs.MATH.H
_CRT_ALLOC_HOOKA type define for the user-defined hook function. Used in _CrtSetAllocHook.CRTDBG.H
_CRT_DUMP_CLIENT,

 _CRT_DUMP_CLIENT_M
A type define for a call-back function that will get called in _CrtMemDumpAllObjectsSince.CRTDBG.H
_CrtMemState structureProvides information about the current state of the C run-time debug heap.CRTDBG.H
_CRT_REPORT_HOOK,

 _CRT_REPORT_HOOKW,

 _CRT_REPORT_HOOKW_M
A type define for a call-back function that will get called in _CrtDbgReport.

The parameters for this function are: report type, output message and the return value from the call-back function.
CRTDBG.H
dev_t, _dev_t short or unsigned integerRepresents device handles.SYS\TYPES.H
_diskfree_t structureContains information about a disk drive. Used by _getdiskfree.DOS.H and DIRECT.H
div_t, ldiv_t and lldiv_t structuresStore values returned by div, ldiv, and lldiv, respectively.STDLIB.H
errno_t integerUsed for a function return type or parameter that deals with the error codes of errno.STDDEF.H,

CRTDEFS.H
_exception structureStores error information for _matherr.MATH.H
_EXCEPTION_POINTERSContains an exception record. See EXCEPTION_POINTERS for more information.FPIEEE.H
FILE structureStores information about current state of stream; used in all stream I/O operations.STDIO.H
_finddata_t, _wfinddata_t, _finddata32_t, _wfinddata32_t, _finddatai64_t, _wfinddatai64_t, __finddata64_t, __wfinddata64_t, __finddata32i64_t, __wfinddata32i64_t, __finddata64i32_t, __wfinddata64i32_t structuresStore file-attribute information returned by _findfirst, _wfindfirst, and related functions and _findnext, _wfindnext and related functions. See Filename Search Functions for information on structure members.IO.H, WCHAR.H
_FPIEEE_RECORD structureContains information pertaining to IEEE floating-point exception; passed to user-defined trap handler by _fpieee_flt.FPIEEE.H
fpos_t (long integer, __int64, or structure, depending on the target platform)Used by fgetpos and fsetpos to record information for uniquely specifying every position within a file.STDIO.H
_fsize_t (unsigned long integer)Used to represent the size of a file.IO.H,

WCHAR.H
_HEAPINFO structureContains information about next heap entry for _heapwalk.MALLOC.H
_HFILE (void *)An operating system file handle.CRTDBG.H
imaxdiv_tThe type of value that's returned by the imaxdiv function, containing both the quotient and the remainder.inttypes.h
ino_t, _ino_t (unsigned short)For returning status information.WCHAR.H
intmax_tA signed integer type capable of representing any value of any signed integer type.stdint.h
intptr_t (long integer or __int64, depending on the target platform)Stores a pointer (or HANDLE) on both Win32 and Win64 platforms.STDDEF.H and other include files
jmp_buf arrayUsed by setjmp and longjmp to save and restore program environment.SETJMP.H
lconv structureContains formatting rules for numeric values in different countries/regions. Used by localeconv.LOCALE.H
_LDOUBLE,

 _LONGDOUBLE,

 _LDBL12 (long double or an unsigned char array)
Use to represent a long double value.STDLIB.H
_locale_t structureStores current locale values; used in all locale specific C run-time libraries.CRTDEF.H
mbstate_tTracks the state of a multibyte character conversion.WCHAR.H
off_t, _off_t long integerRepresents file-offset value.WCHAR.H, SYS\TYPES.H
_onexit_t,

 _onexit_m_t pointer
Returned by _onexit, _onexit_m.STDLIB.H
_PNH pointer to functionType of argument to _set_new_handler.NEW.H
ptrdiff_t (long integer or __int64, depending on the target platform)Result of subtraction of two pointers.CRTDEFS.H
_purecall_handler,

 _purecall_handler_m
A type define for a call-back function that is called when a pure virtual function is called. Used by _get_purecall_handler, _set_purecall_handler. A _purecall_handler function should have a void return type.STDLIB.H
_RTC_error_fn type defineA type define for a function that will handle run-time error checks. Used in _RTC_SetErrorFunc.RTCAPI.H
_RTC_error_fnW type defineA type define for a function that will handle run-time error checks. Used in _RTC_SetErrorFuncW.RTCAPI.H
_RTC_ErrorNumber enumerationDefines error conditions for _RTC_GetErrDesc and _RTC_SetErrorType.RTCAPI.H
_se_translator_functionA type define for a call-back function that translates an exception. The first parameter is the exception code and the second parameter is the exception record. Used by _set_se_translator.EH.H
sig_atomic_t integerType of object that can be modified as atomic entity, even in presence of asynchronous interrupts; used with signal.SIGNAL.H
size_t (unsigned __int64 or unsigned integer, depending on the target platform)Result of sizeof operator.CRTDEFS.H and other include files
_stat structureContains file-status information returned by _stat and _fstat.SYS\STAT.H
__stat64 structureContains file-status information returned by _fstat64 and _stat64, and _wstat64.SYS\STAT.H
_stati64 structureContains file-status information returned by _fstati64, _stati64, and _wstati64.SYS\STAT.H
terminate_function type defineA type define for a call-back function that is called when terminate is called. Used by set_terminate.EH.H
time_t (__int64 or long integer)Represents time values in mktime, time, ctime, _ctime32, _ctime64, _wctime, _wctime32, _wctime64, ctime_s, _ctime32_s, _ctime64_s, _wctime_s, _wctime32_s, _wctime64_s, ctime, _ctime32, _ctime64, _wctime, _wctime32, _wctime64 and gmtime, _gmtime32, _gmtime64. The number of seconds since January 1, 1970, 0:00 UTC. If _USE_32BIT_TIME_T is defined, time_t is a long integer. If not defined, it is a 64-bit integer.TIME.H,

SYS\STAT.H,

SYS\TIMEB.H
__time32_t (long integer)Represents time values in mktime, _mktime32, _mktime64, ctime, _ctime32, _ctime64, _wctime, _wctime32, _wctime64, ctime_s, _ctime32_s, _ctime64_s, _wctime_s, _wctime32_s, _wctime64_s, gmtime, _gmtime32, _gmtime64 and localtime, _localtime32, _localtime64.CRTDEFS.H, SYS\STAT.H,

SYS\TIMEB.H
__time64_t (__int64)Represents time values in mktime, _mktime32, _mktime64, _ctime64, _wctime64, ctime_s, _ctime32_s, _ctime64_s, _wctime_s, _wctime32_s, _wctime64_s, _gmtime64, _localtime64 and _time64.TIME.H,

SYS\STAT.H,

SYS\TIMEB.H
_timeb structureUsed by _ftime and _ftime_s, _ftime32_s, _ftime64_s to store current system time.SYS\TIMEB.H
__timeb32 structureUsed by _ftime, _ftime32, _ftime64 and _ftime_s, _ftime32_s, _ftime64_s to store current system time.SYS\TIMEB.H
__timeb64 structureUsed by _ftime64 and _ftime_s, _ftime32_s, _ftime64_s to store current system time.SYS\TIMEB.H
tm structureUsed by asctime, _wasctime, asctime_s, _wasctime_s, gmtime, _gmtime32, _gmtime64, gmtime_s, _gmtime32_s, _gmtime64_s, localtime, _localtime32, _localtime64, localtime_s, _localtime32_s, _localtime64_s, mktime, _mktime32, _mktime64 and strftime, wcsftime, _strftime_l, _wcsftime_l to store and retrieve time information.TIME.H
uintmax_tAn unsigned integer type capable of representing any value of any unsigned integer type.stdint.h
uintptr_t (long integer or __int64, depending on the target platform)An unsigned integer or unsigned __int64 version of intptr_t.STDDEF.H and other include files
unexpected_functionA type define for a call-back function that is called when unexpected is called. Used by set_unexpected.EH.H
_utimbuf structureStores file access and modification times used by _utime, _wutime and _futime, _futime32, _futime64 to change file-modification dates.SYS\UTIME.H
_utimbuf32 structureStores file access and modification times used by _utime, _utime32, _utime64, _wutime, _wutime32, _wutime64 and _futime, _futime32, _futime64 to change file-modification dates.SYS\UTIME.H
__utimbuf64 structureUsed by _utime64, _wutime64 and _futime64 to store the current time.SYS\UTIME.H
va_list structureUsed to hold information needed by va_arg and va_end macros. Called function declares variable of type va_list that can be passed as argument to another function.STDARG.H,

CRTDEFS.H
wchar_t wide characterUseful for writing portable programs for international markets.STDDEF.H, STDLIB.H,

CRTDEFS.H,

SYS\STAT.H
wctrans_t integerRepresents locale-specific character mappings.WCTYPE.H
wctype_t integerCan represent all characters of any language character set.WCHAR.H,

CRTDEFS.H
wint_t integerType of data object that can hold any wide character or wide end-of-file value.WCHAR.H,

CRTDEFS.H

C Run-Time Library Reference

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