error LNK2019: unresolved external symbol "__declspec(dllimport) private
<p>The project runs correctly under VC6.0, however, after I updated it under VS2012, the following link errors occur:</p>

<pre><code>revel.lib(BaseEncoder.obj) : error LNK2019: unresolved external symbol 
    "__declspec(dllimport) private: void __thiscall std::basic_string&lt;char,struct std::char_traits&lt;char&gt;,class std::allocator&lt;char&gt; &gt;::_Eos(unsigned int)" 
    (__imp_?_Eos@?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@AAEXI@Z) referenced in function 
    "protected: virtual void __thiscall Revel_BaseEncoder::Reset(void)" (?Reset@Revel_BaseEncoder@@MAEXXZ)
</code></pre>

<p>Can anyone help me with this problem? Thanks a lot!</p>
