anchor.diff:    };
   
     enableParallelBuilding = true;
  -
  -  outputs = [ "out" "lib" ];
   
     buildInputs =
       [ icu expat zlib bzip2 python ]
  
positive.code:   withToolset = stdenv.lib.optionalString (toolset != null) " --with-toolset=${toolset}";
  in
  
  stdenv.mkDerivation {
    name = "boost-1.55.0";
  
    meta = {
  
negative.code:       ./b2 -j$NIX_BUILD_CORES -sEXPAT_INCLUDE=${expat.crossDrv}/include -sEXPAT_LIBPATH=${expat.crossDrv}/lib --layout=${layout} --user-config=user-config.jam toolset=gcc-cross variant=${variant} threading=${threading} link=${link} ${cflags} --without-python install
      '';
    };
  }; in res // { lib = res; }
  