std::error_category::operator==,!=,<,<=>

 

C++

Compiler support

Freestanding and hosted

Language

Standard library headers

Named requirements

Feature test macros (C++20)

Language support library

Concepts library (C++20)

Metaprogramming library (C++11)

Diagnostics library

General utilities library

Strings library

Containers library

Iterators library

Ranges library (C++20)

Algorithms library

Numerics library

Localizations library

Input/output library

Filesystem library (C++17)

Regular expressions library (C++11)

Concurrency support library (C++11)

Technical specifications

Symbols index

External libraries

 

Utilities library

Language support Type support (basic types, RTTI) Library feature-test macros (C++20) Dynamic memory management Program utilities Coroutine support (C++20) Variadic functions is_constant_evaluated (C++20) launder (C++17) initializer_list (C++11) source_location (C++20) Three-way comparison (C++20) three_way_comparablethree_way_comparable_with (C++20)(C++20) strong_ordering (C++20) weak_ordering (C++20) partial_ordering (C++20) common_comparison_category (C++20) compare_three_way_result (C++20) compare_three_way (C++20) strong_order (C++20) weak_order (C++20) partial_order (C++20) compare_strong_order_fallback (C++20) compare_weak_order_fallback (C++20) compare_partial_order_fallback (C++20)    is_eqis_neqis_ltis_lteqis_gtis_gteq (C++20)(C++20)(C++20)(C++20)(C++20)(C++20)

General utilities Date and time Function objects Formatting library (C++20) bitset hash (C++11) Relational operators (deprecated in C++20) rel_ops::operator!=rel_ops::operator> rel_ops::operator<=rel_ops::operator>= Integer comparison functions cmp_equalcmp_lesscmp_less_than (C++20)(C++20)(C++20)    cmp_not_equalcmp_greatercmp_greater_than (C++20)(C++20)(C++20) in_range (C++20) Swap and type operations swap ranges::swap (C++20) exchange (C++14) declval (C++11) to_underlying (C++23) forward (C++11) forward_like (C++23) move (C++11) move_if_noexcept (C++11) as_const (C++17) Common vocabulary types pair tuple (C++11) optional (C++17) any (C++17) variant (C++17) tuple_size (C++11) tuple_element (C++11) apply (C++17) make_from_tuple (C++17) expected (C++23) Elementary string conversions to_chars (C++17) from_chars (C++17) chars_format (C++17)

 

Diagnostics library

Exception handling exception uncaught_exceptionuncaught_exceptions (until C++20)(C++17) exception_ptr (C++11) make_exception_ptr (C++11) current_exception (C++11) rethrow_exception (C++11) nested_exception (C++11) throw_with_nested (C++11) rethrow_if_nested (C++11) Exception handling failures terminate terminate_handler get_terminate (C++11) set_terminate bad_exception unexpected (until C++17) unexpected_handler (until C++17) get_unexpected (C++11)(until C++17) set_unexpected (until C++17) Error codes Error codes errno

Exception categories logic_error invalid_argument domain_error length_error out_of_range runtime_error range_error overflow_error underflow_error tx_exception (TM TS) System error support error_category (C++11) generic_category (C++11) system_category (C++11) error_condition (C++11) errc (C++11) error_code (C++11) system_error (C++11) Assertions assert Stacktrace stacktrace_entry (C++23) basic_stacktrace (C++23)

 

std::error_category

Member functions

error_category::error_category

error_category::~error_category

error_category::name

error_category::default_error_condition

error_category::equivalent

error_category::message

error_category::operator==error_category::operator!=error_category::operator<error_category::operator<=> (until C++20)(until C++20)(C++20)

 

bool operator==( const error_category& rhs ) const noexcept;	(1)	(since C++11)
bool operator!=( const error_category& rhs ) const noexcept;	(2)	(since C++11) (until C++20)
bool operator<( const error_category& rhs ) const noexcept;	(3)	(since C++11) (until C++20)
std::strong_ordering operator<=>( const error_category& rhs ) const noexcept;	(4)	(since C++20)

Compares to another error category.

1) Checks whether *this and rhs refer to the same object.

2) Checks whether *this and rhs do not refer to the same object.

3) Orders *this and rhs by the order of this and &rhs. Equivalent to std::less<const error_category*>()(this, &rhs).

4) Orders *this and rhs by the order of this and &rhs. Equivalent to std::compare_three_way()(this, &rhs).

The <, <=, >, >=, and != operators are synthesized from operator<=> and operator== respectively.

(since C++20)

Parameters

rhs

-

specifies the error_category to compare

Return value

1) true if *this and rhs refer to the same object, false otherwise.

2) true if *this and rhs do not refer to the same object, false otherwise.

3) true if *this is less than rhs as defined by the order of this and &rhs.

4) std::strong_order::less if *this is less than rhs as defined by the order of this and &rhs, otherwise std::strong_order::greater if rhs is less than *this in the order, otherwise std::strong_order::equal.