Defined in header <math.h> #define isnormal(arg) /* implementation defined */ (since C99) Determines if the given floating point number arg is normal, i.e. is neither zero, subnormal, infinite, nor NaN. The macro returns an integral value. FLT_EVAL_METHOD is ignored: even if the argument is evaluated with more range and precision than its type, it is first converted to its semantic type, and the classification is based on that. Parameters arg - floating point value

Defined in header <complex.h> float complex conjf( float complex z ); (1) (since C99) double complex conj( double complex z ); (2) (since C99) long double complex conjl( long double complex z ); (3) (since C99) Defined in header <tgmath.h> #define conj( z ) (4) (since C99) 1-3) Computes the complex conjugate of z by reversing the sign of the imaginary part. 4) Type-generic macro: if z has type long double complex, long double imag

Defined in header <wchar.h> struct mbstate_t; (since C95) The type mbstate_t is a trivial non-array type that can represent any of the conversion states that can occur in an implementation-defined set of supported multibyte character encoding rules. Zero-initialized value of mbstate_t represents the initial conversion state, although other values of mbstate_t may exist that also represent the initial conversion state. Possible implementation of mbstate_t is a struct type ho

Defined in header <string.h> void* memchr( const void* ptr, int ch, size_t count ); Finds the first occurrence of ch (after conversion to unsigned char as if by (unsigned char)ch) in the initial count characters (each interpreted as unsigned char) of the object pointed to by ptr. The behavior is undefined if access occurs beyond the end of the array searched. The behavior is undefined if ptr is a null pointer. Parameters ptr - pointer to the object to be examined

Defined in header <signal.h> #define SIG_ERR /* implementation defined */ A value of type void (*)(int). When returned by signal, indicates that an error has occurred. Example #include <stdio.h> #include <stdlib.h> #include <signal.h> void signal_handler(int signal) { printf("Received signal %d\n", signal); } int main(void) { /* Install a signal handler. */ if (signal(SIGTERM, signal_handler) == SIG_ERR) { printf("Error whi

Defined in header <time.h> typedef /* unspecified */ clock_t; Arithmetic (until C11)Real (since C11) type capable of representing the processor time used by a process. It has implementation-defined range and precision. References C11 standard (ISO/IEC 9899:2011): 7.27.1/3 Components of time (p: 388) C99 standard (ISO/IEC 9899:1999): 7.23.1/3 Components of time (p: 338) C89/C90 standard (ISO/IEC 9899:1990): 4.12.1 Components of time See also clock return

Defined in header <stdio.h> int fputs( const char *str, FILE *stream ); (until C99) int fputs( const char *restrict str, FILE *restrict stream ); (since C99) Writes given null-terminated character string to the given output stream. Parameters str - null-terminated character string to be written stream - output stream Return value Non-negative integer on success, EOF on failure. Example fputs() with error checking. #include <

Defined in header <stdio.h> (1) ​int printf( const char *format, ... );​ (until C99) ​int printf( const char *restrict format, ... );​ (since C99) (2) int fprintf( FILE *stream, const char *format, ... ); (until C99) int fprintf( FILE *restrict stream, const char *restrict format, ... ); (since C99) (3) int sprintf( char *buffer, const char *format, ... ); (until C99) int sprintf( char *restrict buffer, const char *restrict format, ... ); (since C

Defined in header <stdlib.h> void* bsearch( const void *key, const void *ptr, size_t count, size_t size, int (*comp)(const void*, const void*) ); (1) void* bsearch_s( const void *key, const void *ptr, rsize_t count, rsize_t size, int (*comp)(const void *, const void *, void *), void *context ); (2) (since C11) 1) Finds an element equal to element pointed to by key in an array pointed to by ptr. The array contains count

Defined in header <stdatomic.h> void atomic_signal_fence( memory_order order ); (since C11) Establishes memory synchronization ordering of non-atomic and relaxed atomic accesses, as instructed by order, between a thread and a signal handler executed on the same thread. This is equivalent to std::atomic_thread_fence, except no CPU instructions for memory ordering are issued. Only reordering of the instructions by the compiler is suppressed as order instructs. For example, wr