Mutable struct vs. class?

Question

I\'m unsure about whether to use a mutable struct or a mutable class. My program stores an array with a lot of objects. I\'ve noticed that using a class doubles the amount of me

Answer 1

Do they really have to be mutable? You could always make it an immutable struct with methods to create a new value with one field different:

struct Block
{
    // I'd definitely get rid of the HasMetaData
    private readonly byte id;
    private readonly BlockMetaData metaData;

    public Block(byte id, BlockMetaData metaData)
    {
        this.id = id;
        this.metaData = metaData;
    }

    public byte Id { get { return id; } }
    public BlockMetaData MetaData { get { return metaData; } }

    public Block WithId(byte newId)
    {
        return new Block(newId, metaData);
    }

    public Block WithMetaData(BlockMetaData newMetaData)
    {
        return new Block(id, newMetaData);
    }
}

I'm still not sure whether I'd make it a struct, to be honest - but I'd try to make it immutable either way, I suspect.

What are your performance requirements in terms of both memory and speed? How close does an immutable class come to those requirements?