Standard C++ Library Reference ISO/IEC (VERSION3)

tm
struct tm;
struct tm contains members that describe various properties of the calendar time. The declaration in this
header leaves struct tm an incomplete type. Include the header <time.h> to complete the type.
ungetwc
wint_t ungetwc(wint_t c, FILE *stream);
If c is not equal to WEOF, the function stores (wchar_t)c in the object whose address is stream and
clears the end-of-file indicator. If c equals WEOF or the store cannot occur, the function returns WEOF;
otherwise, it returns (wchar_t)c. A subsequent library function call that reads a wide character from the
stream stream obtains this stored value, which is then forgotten.
Thus, you can effectively push back a wide character to a stream after reading a wide character.
vfwprintf
int vfwprintf(FILE *stream, const wchar_t *format,
va_list arg);
The function generates formatted text, under the control of the format format and any additional
arguments, and writes each generated wide character to the stream stream. It returns the number of wide
characters generated, or it returns a negative value if the function sets the error indicator for the stream.
The function accesses additional arguments by using the context information designated by ap. The
program must execute the macro va_start before it calls the function, and then execute the macro
va_end after the function returns.
vswprintf
int vswprintf(wchar_t *s, size_t n, const wchar_t *format,
va_list arg);
The function generates formatted text, under the control of the format format and any additional
arguments, and stores each generated wide character in successive locations of the array object whose first
element has the address s. The function concludes by storing a null wide character in the next location of
the array. It returns the number of characters generated -- not including the null wide character.
The function accesses additional arguments by using the context information designated by ap. The
program must execute the macro va_start before it calls the function, and then execute the macro
va_end after the function returns.