The Linux Manuals (man pages) document is an important part of Linux documents. Linux Manuals are organized as several sections. Each section has a group of commands for a specific area in Linux usage, administration or development.
std::fwrite – std::fwrite Synopsis Defined in header<cstdio> std::size_t fwrite(const void *buffer, std::size_t size, std::size_t count, std::FILE *stream); Writes up to count binary objects from the given array buffer to the output stream stream. The objects are written as if by reinterpreting each object as an array of unsigned char and calling std::fputc size times for…
std::fwide – std::fwide Synopsis Defined in header<cwchar> int fwide(std::FILE *stream, int mode); If mode > 0, attempts to make stream wide-oriented. If mode < 0, attempts to make stream byte-oriented. If mode==0, only queries the current orientation of the stream. If the orientation of the stream has already been decided (by executing output or by…
std::future_status – std::future_status Synopsis Defined in header <future> enum class future_status { ready, timeout, (since C++11) deferred }; Specifies state of a future as returned by wait_for and wait_until functions of std::future and std::shared_future. Constant Explanation deferred the shared state contains a deferred function, so the result will be computed only when explicitly requested ready…
std::future_error::what – std::future_error::what Synopsis virtual const char* what() const noexcept; (since C++11) Returns the explanatory string. Parameters (none) Return value Pointer to a null-terminated string with explanatory information. See also returns the error code code (public member function)
std::future_error::future_error – std::future_error::future_error Synopsis explicit future_error( std::future_errc ec ); (since C++17) Constructs a new future error object containing the error code std::make_error_code(ec). Parameters ec – error code Notes There is no standard-compliant way for the user to construct a future_error prior to C++17. C++11 and C++14 depict an exposition-only public constructor taking a std::error_code, and…
std::future_error::code – std::future_error::code Synopsis const std::error_code &code() const noexcept; (since C++ 11) Returns the stored error code. Parameters (none) Return value The stored error code. See also returns the explanatory string specific to the error code what (public member function)
std::future_error – std::future_error Synopsis Defined in header <future> class future_error; (since C++11) The class std::future_error defines an exception object that is thrown on failure by the functions in the thread library that deal with asynchronous execution and shared states (std::future, std::promise, etc). Similar to std::system_error, this exception carries an error code compatible with std::error_code. std-future…
std::future_errc – std::future_errc Synopsis Defined in header <future> enum class future_errc { broken_promise = /* implementation-defined */, future_already_retrieved = /* implementation-defined */, (since C++11) promise_already_satisfied = /* implementation-defined */, no_state = /* implementation-defined */ }; The scoped enumeration std::future_errc defines the error codes reported by std::future and related classes in std::future_error exception objects. Only four…
std::future_category – std::future_category Synopsis Defined in header <future> const std::error_category& future_category() noexcept; (since C++11) Obtains a reference to the static error category object for the errors related to futures and promises. The object is required to override the virtual function error_category::name() to return a pointer to the string "future". It is used to identify error…
std::future<T>::wait_until – std::future<T>::wait_until Synopsis template <class Clock, class Duration> (since C++ 11) std::future_status wait_until(const std::chrono::time_point<Clock, Duration> &timeout_time) const; wait_until waits for a result to become available. It blocks until specified timeout_time has been reached or the result becomes available, whichever comes first. The return value indicates why wait_until returned. The behavior is undefined if valid()==…
std::future<T>::wait_for – std::future<T>::wait_for Synopsis template <class Rep, class Period> (since C++ 11) std::future_status wait_for(const std::chrono::duration<Rep, Period> &timeout_duration) const; Waits for the result to become available. Blocks until specified timeout_duration has elapsed or the result becomes available, whichever comes first. Returns value identifies the state of the result. This function may block for longer than timeout_duration…
std::future<T>::wait – std::future<T>::wait Synopsis void wait() const; (since C++ 11) Blocks until the result becomes available. valid() == true after the call. The behavior is undefined if valid()== false before the call to this function. Parameters (none) Return value (none) Exceptions (none) Notes The implementations are encouraged to detect the case when valid == false…
std::future<T>::valid – std::future<T>::valid Synopsis bool valid() const noexcept; (since C++11) Checks if the future refers to a shared state. This is the case only for futures that were not default-constructed or moved from (i.e. returned by std::promise::get_future(), std::packaged_task::get_future() or std::async()) until the first time get() or share() is called. The behavior is undefined if any…
std::future<T>::share – std::future<T>::share Synopsis std::shared_future<T> share() noexcept; Transfers the shared state of *this, if any, to a std::shared_future object. Multiple std::shared_future objects may reference the same shared state, which is not possible with std::future. After calling share on a std::future, valid() == false. Parameters (none) Return value A std::shared_future object containing the shared state previously…
std::future<T>::operator= – std::future<T>::operator= Synopsis future &operator=(future &&other) noexcept; (1)(since C++ 11) future & operator=(const future &other) = delete; (2)(since C++ 11) Assigns the contents of another future object. 1) Releases any shared state and move-assigns the contents of other to *this. After the assignment, other.valid() == false and this->valid() will yield the same value as…
std::future<T>::get – std::future<T>::get Synopsis T get(); (1) (member only of generic future template) (since C++11) T& get(); (2) (member only of future<T&> template specialization) (since C++11) void get(); (3) (member only of future<void> template specialization) (since C++11) The get method waits until the future has a valid result and (depending on which template is used)…
std::future<T>::~future – std::future<T>::~future Synopsis ~future(); (since C++11) Releases any shared state. This means *if the return object or provider holds the last reference to its shared state, the shared state is destroyed; and *the return object or provider gives up its reference to its shared state; and * these actions will not block for the…
std::future – std::future Synopsis Defined in header <future> template< class T > class future; (1) (since C++11) template< class T > class future<T&>; (2) (since C++11) template<> class future<void>; (3) (since C++11) The class template std::future provides a mechanism to access the result of asynchronous operations: * An asynchronous operation (created via std::async, std::packaged_task, or…
std::function<R(Args…)>::target_type – std::function<R(Args…)>::target_type Synopsis const std::type_info &target_type() const noexcept; (since C++ 11) Returns the type of the stored function. Parameters (none) Return value typeid(T) if the stored function has type T, otherwise typeid(void) Example // Run this code #include <functional> #include <iostream> int f(int a) { return -a; } int main() { // fn1 and…
std::function<R(Args…)>::target – std::function<R(Args…)>::target Synopsis template <class T> (1)(since C++ 11) T *target() noexcept; template <class T> (2)(since C++ 11) const T *target() const noexcept; Returns a pointer to the stored callable function target. Parameters (none) Return value A pointer to the stored function if target_type() == typeid(T), otherwise a null pointer. Example // Run this…