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// Copyright 2013-2025 Antony Polukhin
// Distributed under the Boost Software License, Version 1.0.
// (See the accompanying file LICENSE_1_0.txt
// or a copy at <http://www.boost.org/LICENSE_1_0.txt>.)
//[type_index_derived_example
/*`
The following example shows that `type_info` is able to store the real type, successfully getting through
all the inheritances.
Example works with and without RTTI."
*/
#include <boost/type_index.hpp>
#include <boost/type_index/runtime_cast/register_runtime_class.hpp>
#include <iostream>
struct A {
BOOST_TYPE_INDEX_REGISTER_CLASS
virtual ~A(){}
};
struct B: public A { BOOST_TYPE_INDEX_REGISTER_CLASS };
struct C: public B { BOOST_TYPE_INDEX_REGISTER_CLASS };
struct D: public C { BOOST_TYPE_INDEX_REGISTER_RUNTIME_CLASS() };
void print_real_type(const A& a) {
std::cout << boost::typeindex::type_id_runtime(a).pretty_name() << '\n';
}
int main() {
C c;
const A& c_as_a = c;
print_real_type(c_as_a); // Outputs `struct C`
print_real_type(B()); // Outputs `struct B`
/*`
It's also possible to use type_id_runtime with the BOOST_TYPE_INDEX_REGISTER_RUNTIME_CLASS, which adds additional
information for runtime_cast to work.
*/
D d;
const A& d_as_a = d;
print_real_type(d_as_a); // Outputs `struct D`
}
//] [/type_index_derived_example]
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