[Linker error] undefined reference to `Set<std::string>::contains(std::string const&) const'
<p>I have a class which look likes below:</p>

<pre><code>  template&lt;typename T&gt;
  class Set{
  public:
  bool contains(const T&amp; e) const;
  };
</code></pre>

<p>When i make a member of this class into an another class which is:</p>

<pre><code>  class Dfa {
    private:
    Set&lt;string&gt; F;
    public:
    bool accepts() const
    {
     string temp;
     return F.contains(temp);
    }
    };
</code></pre>

<p>Well, these r just some functions and function statements of the actual class. Can anybody please tell me why do i get the error:   </p>

<pre><code>[Linker error] undefined reference to `Set&lt;std::string&gt;::contains(std::string const&amp;) const' 
</code></pre>

<p>when i compile it and how can i fix this error. Thanks</p>
