Standard Types
The latest version of this topic can be found at Standard Types.
The Microsoft run-time library defines the following standard types and typedefs.
Fixed-width integral types (stdint.h)
| Name | Equivalent built-in type |
|---|---|
| int8_t, uint8_t | signed char, unsigned char |
| int16_t, int16_t | short, unsigned short |
| int32_t, uint32_t | int, unsigned int |
| int64_t, int64_t | long long, unsigned long long |
| int_least8_t, uint_least8_t | signed char, unsigned char |
| int_least16_t, uint_least16_t | short, unsigned short |
| int_least32_t, uint_least32_t | int, unsigned int |
| int_least64_t, uint_least64_t | long long, unsigned long long |
| int_fast8_t, uint_fast8_t | signed char, unsigned char |
| int_fast16_t, uint_fast16_t | int, unsigned int |
| int_fast32_t, uint_fast32_t | int, unsigned int |
| int_fast64_t, uint_fast64_t | long long, unsigned long long |
| intmax_t, uintmax_t | long long, unsigned long long |
| Type | Description | Declared in |
|---|---|---|
clock_t (long) |
Stores time values; used by clock. | TIME.H |
_complex structure |
Stores real and imaginary parts of complex numbers; used by _cabs. | MATH.H |
_CRT_ALLOC_HOOK |
A 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 structure |
Provides 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 integer |
Represents device handles. | SYS\TYPES.H |
_diskfree_t structure |
Contains information about a disk drive. Used by _getdiskfree. | DOS.H and DIRECT.H |
div_t, ldiv_t and lldiv_t structures |
Store values returned by div, ldiv, and lldiv, respectively. | STDLIB.H |
errno_t integer |
Used for a function return type or parameter that deals with the error codes of errno. |
STDDEF.H, CRTDEFS.H |
_exception structure |
Stores error information for _matherr. | MATH.H |
_EXCEPTION_POINTERS |
Contains an exception record. See EXCEPTION_POINTERS for more information. | FPIEEE.H |
FILE structure |
Stores 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 structures |
Store 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 structure |
Contains 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 structure |
Contains information about next heap entry for _heapwalk. | MALLOC.H |
_HFILE (void *) |
An operating system file handle. | CRTDBG.H |
imaxdiv_t |
The 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_t |
A 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 array |
Used by setjmp and longjmp to save and restore program environment. | SETJMP.H |
lconv structure |
Contains 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 structure |
Stores current locale values; used in all locale specific C run-time libraries. | CRTDEF.H |
mbstate_t |
Tracks the state of a multibyte character conversion. | WCHAR.H |
off_t, _off_t long integer |
Represents file-offset value. | WCHAR.H, SYS\TYPES.H |
_onexit_t,_onexit_m_t pointer |
Returned by _onexit, _onexit_m. | STDLIB.H |
_PNH pointer to function |
Type 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 define |
A type define for a function that will handle run-time error checks. Used in _RTC_SetErrorFunc. | RTCAPI.H |
_RTC_error_fnW type define |
A type define for a function that will handle run-time error checks. Used in _RTC_SetErrorFuncW. | RTCAPI.H |
_RTC_ErrorNumber enumeration |
Defines error conditions for _RTC_GetErrDesc and _RTC_SetErrorType. | RTCAPI.H |
_se_translator_function |
A 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 integer |
Type 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 structure |
Contains file-status information returned by _stat and _fstat. | SYS\STAT.H |
__stat64 structure |
Contains file-status information returned by _fstat64 and _stat64, and _wstat64. | SYS\STAT.H |
_stati64 structure |
Contains file-status information returned by _fstati64, _stati64, and _wstati64. | SYS\STAT.H |
terminate_function type define |
A 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 structure |
Used by _ftime and _ftime_s, _ftime32_s, _ftime64_s to store current system time. | SYS\TIMEB.H |
__timeb32 structure |
Used by _ftime, _ftime32, _ftime64 and _ftime_s, _ftime32_s, _ftime64_s to store current system time. | SYS\TIMEB.H |
__timeb64 structure |
Used by _ftime64 and _ftime_s, _ftime32_s, _ftime64_s to store current system time. | SYS\TIMEB.H |
tm structure |
Used 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_t |
An 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_function |
A type define for a call-back function that is called when unexpected is called. Used by set_unexpected. | EH.H |
_utimbuf structure |
Stores file access and modification times used by _utime, _wutime and _futime, _futime32, _futime64 to change file-modification dates. | SYS\UTIME.H |
_utimbuf32 structure |
Stores 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 structure |
Used by _utime64, _wutime64 and _futime64 to store the current time. | SYS\UTIME.H |
va_list structure |
Used 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 character |
Useful for writing portable programs for international markets. | STDDEF.H, STDLIB.H, CRTDEFS.H, SYS\STAT.H |
wctrans_t integer |
Represents locale-specific character mappings. | WCTYPE.H |
wctype_t integer |
Can represent all characters of any language character set. | WCHAR.H, CRTDEFS.H |
wint_t integer |
Type of data object that can hold any wide character or wide end-of-file value. | WCHAR.H, CRTDEFS.H |