A multi_array view has many of the same methods as a multi_array. Do they have a common base that I can use by reference?
void count(Type a) {
// ^^^^ what should I use here?
cout << a.num_elements() << endl;
}
int main() {
boost::multi_array<int, 2> a;
count(a);
count(a[indices[index_range()][index_range()]]);
}
No, there is no common base. You have to use templates. Check out MultiArray Concept and The Boost Concept Check Library.
To be concrete, you need to do this:
template<ArrayType>
void count(ArrayType&& a) {
cout << a.num_elements() << endl;
}
and since the operation is non-modifying, better yet void count(ArrayType const& a).
In my multidimensional array library, there is a common base, so you could avoid a bit of code bloating this way. I would still use the template version because it is conceptually more correct.
#include<multi/array.hpp> // from https://gitlab.com/correaa/boost-multi
#include<iostream>
namespace multi = boost::multi;
template<class Array2D>
auto f1(Array2D const& A) {
std::cout<< A.num_elements() <<'\n';
}
auto f2(multi::basic_array<double, 2> const& A) {
std::cout<< A.num_elements() <<'\n';
}
int main() {
multi::array<double, 2> A({5, 5}, 3.14);
f1( A ); // prints 25
f2( A ); // prints 25
f1( A({0, 2}, {0, 2}) ); // a 2x2 view // prints 4
f2( A({0, 2}, {0, 2}) ); // prints 4
}
