title: Error when using library "xtensor-blas" in C++
body: <p>I have been trying to use the xtensor-blas library for a while, but with no luck. I'm using Windows, G++ 8.1.0 and MinGW-W64. Here is my attempt at a simple example:</p>
  
  <pre><code>#include &lt;iostream&gt;
  #include "xtensor/xarray.hpp"
  #include "xtensor-blas/xlinalg.hpp"
  
  int main()
  {
      xt::xarray&lt;double&gt; a = {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}};
      auto d = xt::linalg::det(a);
  }
  </code></pre>
  
  <p>Here is the error I get </p>
  
  <pre><code>C:\Users\giafc\AppData\Local\Temp\cc498kqV.o:try_xtensor.cpp:(.text$_ZN9cxxlapack5getrfIiEET_S1_S1_PdS1_PS1_[_ZN9cxxlapack5getrfIiEET_S1_S1_PdS1_PS1_]+0x3f): undefined reference to `dgetrf_'
  collect2.exe: error: ld returned 1 exit status
  </code></pre>
  
  <p>Here is the command line I issue to compile the file, where I include the Lapack header directory, I link the Lapack library (where libcblas.a is located), I include the xtensor header directory, the xtl  header directory and the xtensor-blas  header directory.</p>
  
  <pre><code>g++ try2_xtensor.cpp -std=c++14 -I C:/Users/giafc/Anaconda3/pkgs/lapack-3.6.1-h8933c1f_2/Library/include -L C:/Users/giafc/Anaconda3/pkgs/lapack-3.6.1-h8933c1f_2/Library/lib -lcblas -I C:/Users/giafc/Anaconda3/pkgs/xtensor-0.21.5-h7ef1ec2_0/Library/include -I C:/Users/giafc/Anaconda3/pkgs/xtl-0.6.13-h1ad3211_0/Library/include -I C:/Users/giafc/Anaconda3/pkgs/xtensor-blas-0.17.2-hd41736c_0/Library/include
  </code></pre>
  
  <p>Any ideas please?</p>