title: Set Up C++ project with Atom
body: <p>I'm trying set up cpp project with Atom. My project (Picture below). My code (Snippets below). I get error <code>undefined reference to hashCustom::Hash(std::__cxx11::basic_string, std::allocator &gt;)
  collect2: error: ld returned 1 exit status</code>. I did everything from tutorial, in one difference, that tutor used Visual Studio, but it doesn't support Linux. How I can rid error? </p>
  
  <h3><code>hash.h</code></h3>
  
  <pre><code>#include &lt;iostream&gt;
  #include &lt;string&gt;
  using namespace std;
  
  #ifndef HASH_H
  #define HASH_H
  
  class hashCustom {
    public:
    int Hash(string key);
  };
  
  #endif
  </code></pre>
  
  <h3><code>hash.cpp</code></h3>
  
  <pre><code>#include &lt;iostream&gt;
  #include &lt;string&gt;
  #include "../Header Files/hash.h"
  using namespace std;
  
  int hashCustom::Hash(string key) {
    int index;
    index = key.length();
    return index;
  }
  </code></pre>
  
  <h3><code>main.cpp</code></h3>
  
  <pre><code>#include &lt;iostream&gt;
  #include &lt;string&gt;
  #include "../Header Files/hash.h"
  using namespace std;
  
  int main() {
  
    hashCustom hashObj;
    cout &lt;&lt; hashObj.Hash("Number") &lt;&lt; endl;
    return 0;
  }
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/jRLsH.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/jRLsH.png" alt="enter image description here"></a></p>