C++ Type_info Library - operator== Function

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Description

It returns whether the types identified by two type_info objects are the same.

Declaration

Following is the declaration for std::type_info::operator==

C++98

	
bool operator== (const type_info& rhs) const;

C++11

bool operator== (const type_info& rhs) const noexcept;

Parameters

rhs − It identify the object type.

Return Value

It returns whether the types identified by two type_info objects are the same.

Exceptions

No-throw guarantee − this member function never throws exceptions.

Data races

The locale object is modified.

Example

In below example for std::type_info::operator==.

#include <iostream>
#include <typeinfo>

struct Base {};
struct Derived : Base {};
struct Poly_Base {virtual void Member(){}};
struct Poly_Derived: Poly_Base {};

typedef int my_int_type;

int main() {
   std::cout << std::boolalpha;

   std::cout << "int vs my_int_type: ";
   std::cout << ( typeid(int) == typeid(my_int_type) ) << '\n';

   std::cout << "Base vs Derived: ";
   std::cout << ( typeid(Base)==typeid(Derived) ) << '\n';

   Base* pbase = new Derived;

   std::cout << "Base vs *pbase: ";
   std::cout << ( typeid(Base)==typeid(*pbase) ) << '\n';

   Poly_Base* ppolybase = new Poly_Derived;

   std::cout << "Poly_Base vs *ppolybase: ";
   std::cout << ( typeid(Poly_Base)==typeid(*ppolybase) ) << '\n';

   return 0;
}

The output should be like this −

int vs my_int_type: true
Base vs Derived: false
Base vs *pbase: true
Poly_Base vs *ppolybase: false