title: How to use libraries compiled with MingW in MSVC?
body: <p>I have compiled several libraries with MingW/MSYS... the generated static libraries are always .a files.
  When I try to link the library with a MSVC project, Visual Studio throws 'unresolved external symbols' ... It means that the .a static library is incompatible with MS C++ Linker. I presume it has to be converted to a MSVC compatible .lib file.</p>
  
  <p>Either .a and .lib are just AR archives of .o or .obj files, so is there any way how to use MingW compiled libs in a MSVC project? Or do I have to compile/link everything just in one compiler/linker - MSVC only/MingW only?
  The MingW compiler is said to be compatible with MSVC.</p>
  
  <p>I read a few threads about this topic, but they mostly say that renaming the file to .lib should do the work, but it unfortunately doesn't work for me.</p>
  
  <p>The libraries Im trying to link are written in C.</p>
  
  <p>MSVC Linker throws errors like: </p>
  
  <pre><code>error LNK2019: unresolved external symbol "int __cdecl openssl_call(struct ssl_State *,int,int,int)" (?openssl_call@@YAHPAUssl_State@@HHH@Z) referenced in function _main MyAPP.obj
  </code></pre>
  
  <p>... and 4 more same errors referring to other functions called from my app.</p>
  
  <p>Thanks for any advice.</p>