title: What does a unresolved external symbol error mean?
body: <p>I'm programming an easy "bid on a house" application in C++. I compile and get this error msg: </p>
  
  <pre><code>1&gt;Hus.obj : error LNK2019: unresolved external symbol "public: __thiscall 
  Bud::Bud(void)" (??0Bud@@QAE@XZ) referenced in function "public: __thiscall 
  Hus::Hus(int,class Person,class std::basic_string&lt;char,struct 
  std::char_traits&lt;char&gt;,class std::allocator&lt;char&gt; &gt;)" 
  (??0Hus@@QAE@HVPerson@@V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@Z)
  1&gt;F:\c++\prosjekter\Øving 4\Ov4Oppg1\Debug\Ov4Oppg1.exe : fatal error LNK1120: 1 
  unresolved externals
  </code></pre>
  
  <p>Anyone have a clue?</p>