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> Mutable struct fields may now be annotated as const to prevent changing them after construction, providing for greater clarity and optimization ability of these objects

So will these be exactly like non-mutable structs?

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No, it'd be a hybrid between a mutable and immutable struct. This allows you to control on a per-field basis whether the field is mutable or immutable.

I get that, but my question is: if a type is mutable and I instantiate with const, will the exact same optimizations available?

A mutable struct which labels all fields as const is an immutable struct. And yes it optimizes.

this isn't about instantiating a struct, this is about specifying that the field of a struct is const.

Oh fields. Got it.

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