Constructor using struct

[LeonardJohard]

It would be convenient to have a StructArray constructor based on an existing struct, for example:

structarray = StructArray(struct)

where struct is any struct. Any non-numerical fields would be ignored and not added to the new struct.

Application could be in various types of data storage, for example in simulations, where a struct contains all the information of some object, while StructArray constructor prepares the numerical fields for efficient numerical operations.