std::error_code:: error_code

From cppreference.com

error_code ( ) noexcept ;	(1)	(since C++11)
error_code ( int ec, const error_category & ecat ) noexcept ;	(2)	(since C++11)
template < class ErrorCodeEnum > error_code ( ErrorCodeEnum e ) noexcept ;	(3)	(since C++11)
error_code ( const error_code & other ) = default ;	(4)	(since C++11) (implicitly declared)
error_code ( error_code && other ) = default ;	(5)	(since C++11) (implicitly declared)

Constructs new error code.

1) Constructs error code with default value. Equivalent to error_code ( 0 , std:: system_category ( ) ) .

2) Constructs error code with ec as the platform-dependent error code and ecat as the corresponding error category .

3) Constructs error code from an error code enum e . Equivalent to make_error_code ( e ) , where


        make_error_code

is only found by argument-dependent lookup . This overload participates in overload resolution only if std:: is_error_code_enum < ErrorCodeEnum > :: value is true .

4,5) Implicitly defined copy constructor and move constructor. Initializes the error code with the contents of the other .

other	-	another error code to initialize with
ec	-	platform dependent error code to construct with
ecat	-	error category corresponding to ec
e	-	error code enum to construct with

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR	Applied to	Behavior as published	Correct behavior
LWG 3629	C++11	only `std::make_error_code` overloads were used	ADL-found overloads are used

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Feature test macros (C++20)
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Member functions
error_code::error_code
error_code::operator=
error_code::assign
Modifiers
error_code::clear
Observers
error_code::value
error_code::category
error_code::default_error_condition
error_code::message
error_code::operator bool
Non-member functions
operator== operator!= operator< operator<=> (until C++20) (until C++20) (C++20)
operator<<
Helper classes
is_error_code_enum
hash <std::error_code>

make_error_code (std::errc) (C++11)	creates error code value for `errc` enum e (function)
make_error_code (std::io_errc) (C++11)	constructs an iostream error code (function)
make_error_code (std::future_errc) (C++11)	constructs a future error code (function)