| // Boost shared_ptr_example.cpp --------------------------------------------// |
| |
| // Copyright Beman Dawes 2001. Distributed under the Boost |
| // Software License, Version 1.0. (See accompanying file |
| // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) |
| |
| |
| // See http://www.boost.org/libs/smart_ptr for documentation. |
| |
| // Revision History |
| // 21 May 01 Initial complete version (Beman Dawes) |
| |
| // The original code for this example appeared in the shared_ptr documentation. |
| // Ray Gallimore pointed out that foo_set was missing a Compare template |
| // argument, so would not work as intended. At that point the code was |
| // turned into an actual .cpp file so it could be compiled and tested. |
| |
| #include <vector> |
| #include <set> |
| #include <iostream> |
| #include <algorithm> |
| #include <boost/shared_ptr.hpp> |
| |
| // The application will produce a series of |
| // objects of type Foo which later must be |
| // accessed both by occurrence (std::vector) |
| // and by ordering relationship (std::set). |
| |
| struct Foo |
| { |
| Foo( int _x ) : x(_x) {} |
| ~Foo() { std::cout << "Destructing a Foo with x=" << x << "\n"; } |
| int x; |
| /* ... */ |
| }; |
| |
| typedef boost::shared_ptr<Foo> FooPtr; |
| |
| struct FooPtrOps |
| { |
| bool operator()( const FooPtr & a, const FooPtr & b ) |
| { return a->x > b->x; } |
| void operator()( const FooPtr & a ) |
| { std::cout << a->x << "\n"; } |
| }; |
| |
| int main() |
| { |
| std::vector<FooPtr> foo_vector; |
| std::set<FooPtr,FooPtrOps> foo_set; // NOT multiset! |
| |
| FooPtr foo_ptr( new Foo( 2 ) ); |
| foo_vector.push_back( foo_ptr ); |
| foo_set.insert( foo_ptr ); |
| |
| foo_ptr.reset( new Foo( 1 ) ); |
| foo_vector.push_back( foo_ptr ); |
| foo_set.insert( foo_ptr ); |
| |
| foo_ptr.reset( new Foo( 3 ) ); |
| foo_vector.push_back( foo_ptr ); |
| foo_set.insert( foo_ptr ); |
| |
| foo_ptr.reset ( new Foo( 2 ) ); |
| foo_vector.push_back( foo_ptr ); |
| foo_set.insert( foo_ptr ); |
| |
| std::cout << "foo_vector:\n"; |
| std::for_each( foo_vector.begin(), foo_vector.end(), FooPtrOps() ); |
| |
| std::cout << "\nfoo_set:\n"; |
| std::for_each( foo_set.begin(), foo_set.end(), FooPtrOps() ); |
| std::cout << "\n"; |
| |
| // Expected output: |
| // |
| // foo_vector: |
| // 2 |
| // 1 |
| // 3 |
| // 2 |
| // |
| // foo_set: |
| // 3 |
| // 2 |
| // 1 |
| // |
| // Destructing a Foo with x=2 |
| // Destructing a Foo with x=1 |
| // Destructing a Foo with x=3 |
| // Destructing a Foo with x=2 |
| |
| return 0; |
| } |
| |