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POC++:member reference or pointer?
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  1. POC++:member reference or pointer?
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    copied!<p>I have a collection (currently <code>boost::ptr_vector</code>) of objects (lets call this vec) that needs to be passed to a few functors. I want all of the functors to have a reference/pointer to the same vec which is essentially a cache so that each functor has the same data cache. There are three ways that I can think of doing this:</p> <ol> <li><p>Passing a <code>boost::ptr_vector&lt;object&gt;&amp;</code> to the constructor of <code>Functor</code> and having a <code>boost::ptr_vector&lt;object&gt;&amp;</code> member in the Functor class</p></li> <li><p>Passing a <code>boost::ptr_vector&lt;object&gt;*</code> to the constructor of Functor and having a <code>boost::ptr_vector&lt;object&gt;*</code> member in the Functor class</p></li> <li><p>avoid the use of <code>boost::ptr_vector</code> and directly pass an array (<code>object*</code>) to the constructor</p></li> </ol> <p>I have tried to use method 3, but have been told constantly that I should use a vector instead of a raw pointer. So, I tried method 2 but this added latency to my program due to the extra level of indirection added by the pointer. I am using method 1 at the moment, however I may need to reassign the cache during the lifetime of the functor (as the data cache may change) so this may not be an appropriate alternative.</p> <p>Which I don't fully understand. I assume somewhere along the way the functor is being copied (although these are all stored in a ptr_vector themselves).</p> <p>Is method 3 the best for my case? method 2, is too slow (latency is very crucial), and as for method 1, I have been advised time and again to use vectors instead.</p> <p>Any advice is much appreciated</p>
 

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