Improve filledArray utility if type is not default constructible
Summary
If a type is not default-constructible, it cannot be used to create a filled array with the utility Dune::filledArray
. This MR fixes this issue by relying on copy-construction only.
Example
struct A {
A(int) {}
}; // not default-constructible
// ...
auto a = Dune::filledArray<N>(A(42)); // ERROR before this MR, OK now
Edited by Simon Praetorius