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

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bool operator==( const error_category& rhs ) const;
(1) (since C++11)
bool operator!=( const error_category& rhs ) const;
(2) (since C++11)
bool operator<( const error_category& rhs ) const;
(3) (since C++11)

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).

Parameters

code - specifies the error code to compare
condition - specifies the error condition 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.

Exceptions

noexcept specification:  
noexcept