Defined in header <time.h> struct tm *gmtime( const time_t *time ); (1) struct tm *gmtime_s(const time_t *restrict time, struct tm *restrict result); (2) (since C11) 1) Converts given time since epoch (a time_t value pointed to by time) into calendar time, expressed in Coordinated Universal Time (UTC) in the struct tm format. The result is stored in static storage and a pointer to that static storage is returned. 2) Same as (1), except that the function uses user-pr

Usage _Alignof operator

Defined in header <wchar.h> size_t wcsftime( wchar_t* str, size_t count, const wchar_t* format, tm* time ); (since C95) Converts the date and time information from a given calendar time time to a null-terminated wide character string str according to format string format. Up to count bytes are written. Parameters str - pointer to the first element of the wchar_t array for output count - maximum number of wide characters to write format - pointer to a nul

Terminates current function and returns specified value to the caller function. Syntax return expression ; (1) return ; (2) Explanation 1) Evaluates the expression, terminates the current function and returns the result of the expression to the caller (the value returned becomes the value of the function call expression). Only valid if the function return type is not void. 2) Terminates the current function. Only valid if the function return type is void. If the type of th

Queries size of the object or type. Used when actual size of the object must be known. Syntax sizeof( type ) (1) sizeof expression (2) Both versions return a value of type size_t. Explanation 1) Returns the size, in bytes, of the object representation of type 2) Returns the size, in bytes, of the object representation of the type of expression Notes Depending on the computer architecture, a byte may consist of 8 or more bits, the exact number provided as CHAR_BIT. si

Defined in header <threads.h> int thrd_detach( thrd_t thr ); (since C11) Detaches the thread identified by thr from the current environment. The resources held by the thread will be freed automatically once the thread exits. Parameters thr - identifier of the thread to detach Return value thrd_success if successful, thrd_error otherwise. References C11 standard (ISO/IEC 9899:2011): 7.26.5.3 The thrd_detach function (p: 383-384) See also thrd_join

Defined in header <stdatomic.h> #define ATOMIC_BOOL_LOCK_FREE /* implementation-defined */ #define ATOMIC_CHAR_LOCK_FREE /* implementation-defined */ #define ATOMIC_CHAR16_T_LOCK_FREE /* implementation-defined */ #define ATOMIC_CHAR32_T_LOCK_FREE /* implementation-defined */ #define ATOMIC_WCHAR_T_LOCK_FREE /* implementation-defined */ #define ATOMIC_SHORT_LOCK_FREE /* implementation-defined */ #define ATOMIC_INT_LOCK_FREE /* implementation-defined */ #define ATOM

An identifier is an arbitrarily long sequence of digits, underscores, lowercase and uppercase Latin letters, and Unicode characters specified using \u and \U escape notation (since C99). A valid identifier must begin with a non-digit character (Latin letter, underscore, or Unicode non-digit character (since C99)). Identifiers are case-sensitive (lowercase and uppercase letters are distinct). It is implementation-defined if raw (not escaped) Unicode characters are allowed in identifiers. (since

Increment/decrement operators are unary operators that increment/decrement the value of a variable by 1. They can have postfix form: expr ++ expr -- As well as the prefix form: ++ expr -- expr The operand expr of both prefix and postfix increment or decrement must be a modifiable lvalue of integer type (including _Bool and enums), real floating type, or a pointer type. It may be cvr-qualified, unqualified, or atomic. The result of the postfix increment and decrement

The C programming language, as of C99, supports Boolean arithmetic with the built-in type _Bool (see _Bool). When the header <stdbool.h> is included, the Boolean type is also accessible as bool. Standard logical operators &&, ||, ! can be used with the Boolean type in any combination. A program may undefine and perhaps then redefine the macros bool, true and false. Macros Macro name Expands to bool _Bool true integer constant 1 false integer constant 0 __bool_t