std::error_category::operator==,!=,<
| bool operator==( const error_category& rhs ) const noexcept; | (1) | (since C++11) | 
| bool operator!=( const error_category& rhs ) const noexcept; | (2) | (since C++11) | 
| bool operator<( const error_category& rhs ) const noexcept; | (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.
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