System.Nullable — parametrized struct
— /also-rans/ —
Decimal – just another Float
all “simple types”
all enum types
I feel these are often immutable. Even if mutable, given the pbclone semantics it’s almost useless to provide mutator methods anyway. However, to understand mutable structs, consider the most improtant value type — int.
In a standard “
for (int idx…” idx is mutable, but when you make a copy of idx (or pass in/out a function) the copy is detatched from the mutable int variable.