types::ndarray<T, M> reshape(types::ndarray<T, N> const &expr,
types::array<long, M> const &new_shape)
{
auto where = std::find(new_shape.begin(), new_shape.end(), -1);
if (where != new_shape.end()) {
auto auto_shape = new_shape;
auto_shape[where - new_shape.begin()] =
expr.flat_size() / std::accumulate(new_shape.begin(),
new_shape.end(), -1L,
std::multiplies<long>());
return expr.reshape(auto_shape);
} else
return expr.reshape(new_shape);
}
