ALUGrid is needed to avoid unresolved symbols if dune-grid was
compiled with it. METIS is used by the parallel version of
ALUGrid. (Although it is not open source...)
This module sets individual flags for each feature; there is not one
"CXX11Features_FOUND" flags which is set. Thus, when putting the
module as REQUIRED, the only consequence is that we cannot disable
searching for it.
Instead, we make it optional, meaning that the flags won't get set if
it isn't included and the dependent modules will adjust accordingly.
If dune-grid has been compiled with _GLIBCXX_DEBUG, linking the test
program will fail since probing doesn't get the flags that are specified
for the main project, and thus configuration halts. Instead, we use a
smaller test program which doesn't need proper STL linkage to compile
and link.
Andreas Lauser
Andreas Lauser
Roland Kaufmann