include(CheckCXXSourceCompiles) # support for C++17's variant implementation check_cxx_source_compiles(" #include <variant> int main() { std::variant<int,double> a; a = 1; a = 2.0; bool positive = std::visit([](auto&& x) { return x > 0; }, a); } " DUNE_HAVE_CXX_VARIANT )
