title: C++ error: Member declaration not found
body: <p>I am a c++ newbie. Today, I have a problem:
  in header file, I define a class:</p>
  
  <pre><code>template&lt;class T&gt; class Ptr_to_const {
  private:
      Array_Data&lt;T&gt;* ap;
      unsigned sub;
  
  public:
          ...
  
      Ptr_to_const&lt;T&gt; &amp; operator=(const Ptr_to_const&lt;T&gt; &amp; p);
  
  };
  </code></pre>
  
  <p>and in source file, I program as:</p>
  
  <pre><code>template&lt;class T&gt; Ptr_to_const&lt;T&gt;&amp; Ptr_to_const&lt;T&gt;::operator=(
          const Ptr_to_const&lt;T&gt; &amp; p) {
           ...
      return *this;
  }
  </code></pre>
  
  <p>when compiled, compiler always say: '<strong>Member declaration not found</strong>'.
  <strong>why?</strong></p>
  
  <p>I use <strong>eclipse CDT+Cygwin GCC</strong></p>
  
  <p>thank you very much!</p>