graph-tool compile fails with OpenMP 4.5
OpenMP 4.5 omp's parallel if clause has a "parallel"-named qualifier, which causes the compilation problem in files that use the variable named "parallel".
Replacing the variable name "parallel" with "parallel_enabled" yields a successful compile. Patch files attached.
This fix will allow graph-tool OpenMP support on OS X with the Macports command:
sudo port install py-graph-tool configure.compiler=macports-clang-3.9 configure.args-append=--enable-openmp