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example/RefCountPtr/cxx_main.cpp

This is an example of how to use the Teuchos::RCP class.

/*
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// ***********************************************************************
//
// Teuchos: Common Tools Package
// Copyright (2004) Sandia Corporation
//
// Under terms of Contract DE-AC04-94AL85000, there is a non-exclusive
// license for use of this work by or on behalf of the U.S. Government.
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// modification, are permitted provided that the following conditions are
// met:
//
// 1. Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
//
// 3. Neither the name of the Corporation nor the names of the
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY SANDIA CORPORATION "AS IS" AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
// PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL SANDIA CORPORATION OR THE
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// Questions? Contact Michael A. Heroux (maherou@sandia.gov)
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*/
#include "Teuchos_RCP.hpp"
#include "Teuchos_Version.hpp"
class A {
public:
A() {}
virtual ~A(){}
virtual void f(){}
};
class B1 : virtual public A {};
class B2 : virtual public A {};
class C : public B1, public B2 {};
using namespace Teuchos;
int main(int argc, char* argv[])
{
std::cout << Teuchos::Teuchos_Version() << std::endl << std::endl;
// Create some reference-counted pointers.
// Create a reference-counted NULL pointer of type A.
RCP<A> a_null_ptr;
// Create a reference-counted pointer of non-const type A.
RCP<A> a_ptr = rcp(new A);
// Create a reference-counted pointer of const type A.
RCP<const A> ca_ptr = rcp(new A);
// Create a const reference-counted pointer of non-const type A.
const RCP<A> a_cptr = rcp(new A);
// Create a const reference-counted pointer of const type A.
const RCP<const A> ca_cptr = rcp(new A);
// Perform implicit conversions between a derived class and its base class.
RCP<B1> b1_ptr = rcp(new B1);
RCP<A> a_ptr1 = b1_ptr;
/* Other non-implicit type conversions like static, dynamic, or const casts
can be taken care of by non-member template functions.
*/
RCP<const C> c_ptr = rcp(new C);
// Implicit cast from C to B2.
RCP<const B2> b2_ptr = c_ptr;
// Safe cast, type-checked, from C to A.
RCP<const A> ca_ptr1 = rcp_dynamic_cast<const A>(c_ptr);
// Unsafe cast, non-type-checked, from C to A.
RCP<const A> ca_ptr2 = rcp_static_cast<const A>(c_ptr);
// Cast away const from B2.
RCP<B2> nc_b2_ptr = rcp_const_cast<B2>(b2_ptr);
/* Using a reference-counted pointer is very similar to using a raw C++ pointer. Some
of the operations that are common to both are:
*/
a_ptr2 = rcp(new A), // Initialize reference-counted pointers.
a_ptr3 = rcp(new A); // ""
A *ra_ptr2 = new A, // Initialize non-reference counted pointers.
*ra_ptr3 = new A; // ""
a_ptr2 = rcp(ra_ptr3); // Assign from a raw pointer (only do this once!)
a_ptr3 = a_ptr1; // Assign one smart pointer to another.
a_ptr2 = rcp(ra_ptr2); // Assign from a raw pointer (only do this once!)
a_ptr2->f(); // Access a member of A using ->
ra_ptr2->f(); // ""
*a_ptr2 = *a_ptr3; // Dereference the objects and assign.
*ra_ptr2 = *ra_ptr3; // ""
// Get the raw C++ pointer.
A* true_ptr = 0;
true_ptr = a_ptr1.get();
TEUCHOS_ASSERT_EQUALITY(true_ptr, b1_ptr.get());
return 0;
}