uires that your compiler is appropriately configured.</p>
  <p><code>variant=</code><i>string&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; string </i>is
  <code>debug</code> or <code>release</code>.</p>
  <p><code>toolset=</code><i>string</i>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; The C++
  compiler to use. For example, <code>gcc-4.9</code>, <code>clang-3.3</code>,
  <code>or msvc-14.0</code>.</p>
  <p><code>include=</code><i>string&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </i>
  Additional include paths for C and C++ compilers.</p>
  <p><co