std::type_info::operator==,std::type_info::operator!=(3)

NAME
std::type_info::operator==,std::type_info::operator!= - std::type_info::operator==,std::type_info::operator!=

Synopsis
   bool operator==( const type_info& rhs ) const; (until C++11)
   bool operator==( const type_info& rhs ) const (since C++11)
   noexcept; (until C++23)
   constexpr bool operator==( const type_info& rhs (1) (since C++23)
   ) const noexcept;
   bool operator!=( const type_info& rhs ) const; (until C++11)
   bool operator!=( const type_info& rhs ) const (2) (since C++11)
   noexcept; (until C++20)
   Checks if the objects refer to the same types.
   The != operator is synthesized from operator==. (since C++20)

Parameters
   rhs - another type information object to compare to

Return value
   true if the comparison operation holds true, false otherwise.

Notes
        Feature-test macro Value Std Feature
   __cpp_lib_constexpr_typeinfo 202106L (C++23) Constexpr for
                        std::type_info::operator==

Example
// Run this code
 #include <iostream>
 #include <string>
 #include <typeinfo>
 #include <utility>
 class person
 {
 public:
     explicit person(std::string n) : name_(std::move(n)) {}
     virtual const std::string& name() const { return name_; }
 private:
     std::string name_;
 };
 class employee : public person
 {
 public:
     employee(std::string n, std::string p)
         : person(std::move(n)), profession_(std::move(p)) {}
     const std::string& profession() const { return profession_; }
 private:
     std::string profession_;
 };
 void print_info(const person& p)
 {
     if (typeid(person) == typeid(p))
         std::cout << p.name() << " is not an employee\n";
     else if (typeid(employee) == typeid(p))
     {
         std::cout << p.name() << " is an employee ";
         auto& emp = dynamic_cast<const employee&>(p);
         std::cout << "who works in " << emp.profession() << '\n';
     }
 }
 int main()
 {
     print_info(employee{"Paul","Economics"});
     print_info(person{"Kate"});
 #if __cpp_lib_constexpr_typeinfo
     if constexpr (typeid(employee) != typeid(person)) // C++23
         std::cout << "class `employee` != class `person`\n";
 #endif
 }

Possible output:
 Paul is an employee who works in Economics
 Kate is not an employee
 class `employee` != class `person`

See also
          checks whether the referred type precedes referred type of another type_info
   before object in the implementation defined order, i.e. orders the referred types
          (public member function)