std::error_code(3)

NAME
std::error_code - std::error_code

Synopsis
   Defined in header <system_error>
   class error_code; (since C++11)
   std::error_code is a platform-dependent error code. Each std::error_code object
   holds an error code originating from the operating system or some low-level
   interface and a pointer to an object of type std::error_category, which corresponds
   to the said interface. The error code values may be not unique across different
   error categories.

Member functions
   constructor constructs an error code
                        (public member function)
   operator= assigns another error code
                        (public member function)
   assign assigns another error code
                        (public member function)

Modifiers
   clear sets the error_code to value 0 in system_category
                        (public member function)

Observers
   value obtains the value of the error_code
                        (public member function)
   category obtains the error_category for this error_code
                        (public member function)
   default_error_condition obtains the error_condition for this error_code
                        (public member function)
   message obtains the explanatory string for this error_code
                        (public member function)
   operator bool checks if the value is non-zero
                        (public member function)

Non-member functions
   operator==
   operator!=
   operator< compares two error_codes
   operator<=> (function)
   (removed in C++20)
   (removed in C++20)
   (C++20)
   operator<< outputs the value and the category name to an output stream
                      (function)

Helper classes
   is_error_code_enum identifies a class as an error_code enumeration
   (C++11) (class template)
   std::hash<std::error_code> hash support for std::error_code
   (C++11) (class template specialization)

See also
   error_condition holds a portable error code
   (C++11) (class)
   error_category base class for error categories
   (C++11) (class)
   make_error_code(std::errc) constructs an std::errc error code
   (C++11) (function)