30 Input/output library [input.output]

30.5 Iostreams base classes [iostreams.base]

30.5.6 ios_­base manipulators [std.ios.manip] Error reporting [error.reporting]

error_code make_error_code(io_errc e) noexcept;
Returns: error_­code(static_­cast<int>(e), iostream_­category()).
error_condition make_error_condition(io_errc e) noexcept;
Returns: error_­condition(static_­cast<int>(e), iostream_­category()).
const error_category& iostream_category() noexcept;
Returns: A reference to an object of a type derived from class error_­category.
The object's default_­error_­condition and equivalent virtual functions shall behave as specified for the class error_­category.
The object's name virtual function shall return a pointer to the string "iostream".