public member function

std::relational operators (error_category)

bool operator== (const error_category& rhs) const noexcept;
bool operator!= (const error_category& rhs) const noexcept;
bool operator<  (const error_category& rhs) const noexcept;
Relational operators
These member functions compare whether two error_category objects are the same.

Two error_category objects only compare equal if they have the same address in memory:
this == &rhs

The less-than relational operator (3) returns whether the left-hand side operand refers to an object whose reference goes before rhs in a total ordering of pointers, as if defined as:
bool error_category::operator< (const error_category& rhs) const noexcept {
  return less <const error_category*>()(this,&rhs);


Another error_category object.

Return value

true if both objects are the same, false otherwise.