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POHow to use std::find/std::find_if with a vector of custom class objects?
 

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  1. POHow to use std::find/std::find_if with a vector of custom class objects?
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    <p>I have a class representing a user called <code>Nick</code> and I want to use <code>std::find_if</code> on it, where I want to find if the userlist vector has an object included with the same username I pass in. I did a few attempts by trying to create a new <code>Nick</code> object for the username I want to test and overloading the <code>== operator</code> and then trying to use <code>find/find_if</code> on the object:</p> <pre><code> std::vector&lt;Nick&gt; userlist; std::string username = "Nicholas"; if (std::find(userlist.begin(), userlist.end(), new Nick(username, false)) != userlist.end())) { std::cout &lt;&lt; "found"; } </code></pre> <p>I have overloaded the <code>== operator</code> so comparing Nick == Nick2 should work, but the function returns <code>error C2678: binary '==' : no operator found which takes a left-hand operand of type 'Nick' (or there is no acceptable conversion)</code>.</p> <p>Here is my Nick class for reference:</p> <pre><code>class Nick { private: Nick() { username = interest = email = ""; is_op = false; }; public: std::string username; std::string interest; std::string email; bool is_op; Nick(std::string d_username, std::string d_interest, std::string d_email, bool d_is_op) { Nick(); username = d_username; interest = d_interest; email = d_email; is_op = d_is_op; }; Nick(std::string d_username, bool d_is_op) { Nick(); username = d_username; is_op = d_is_op; }; friend bool operator== (Nick &amp;n1, Nick &amp;n2) { return (n1.username == n2.username); }; friend bool operator!= (Nick &amp;n1, Nick &amp;n2) { return !(n1 == n2); }; }; </code></pre>
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