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POExample to use shared_ptr?
 

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    <p>Hi I asked a question today about <a href="https://stackoverflow.com/questions/3475030/different-types-of-objects-in-the-same-vector-array">How to insert different types of objects in the same vector array </a> and my code in that question was </p> <pre><code> gate* G[1000]; G[0] = new ANDgate() ; G[1] = new ORgate; //gate is a class inherited by ANDgate and ORgate classes class gate { ..... ...... virtual void Run() { //A virtual function } }; class ANDgate :public gate {..... ....... void Run() { //AND version of Run } }; class ORgate :public gate {..... ....... void Run() { //OR version of Run } }; //Running the simulator using overloading concept for(...;...;..) { G[i]-&gt;Run() ; //will run perfectly the right Run for the right Gate type } </code></pre> <p>and I wanted to use vectors so someone wrote that I should do that :</p> <pre><code>std::vector&lt;gate*&gt; G; G.push_back(new ANDgate); G.push_back(new ORgate); for(unsigned i=0;i&lt;G.size();++i) { G[i]-&gt;Run(); } </code></pre> <p>but then he and many others suggested that I would better use <a href="http://www.boost.org/doc/libs/1_43_0/libs/ptr_container/doc/guidelines.html" rel="noreferrer">Boost pointer containers<br> </a> or <code>shared_ptr</code>. I have spent the last 3 hours reading about this topic, but the documentation seems pretty advanced to me . ****Can anyone give me a small code example of <code>shared_ptr</code> usage and why they suggested using <code>shared_ptr</code>. Also are there other types like <code>ptr_vector</code>, <code>ptr_list</code> and <code>ptr_deque</code>** **</p> <p>Edit1: I have read a code example too that included:</p> <pre><code>typedef boost::shared_ptr&lt;Foo&gt; FooPtr; ....... int main() { std::vector&lt;FooPtr&gt; foo_vector; ........ FooPtr foo_ptr( new Foo( 2 ) ); foo_vector.push_back( foo_ptr ); ........... } </code></pre> <p>And I don't understand the syntax!</p>
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    1. COWhich syntax don't you understand? The first line of `main` creates a vector that can contain shared pointers to a type called `Foo`; the second one creates a `Foo` using `new`, and a shared pointer to manage it; the third puts a copy of the shared pointer into the vector.
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