By ‘constant stack value’, I was referring to ‘effectively constant’ stack values, i.e. ones who aren’t reassigned in the scope or passed by mutable reference (

By ‘constant stack value’, I was referring to ‘effectively constant’ stack values, i.e. ones who aren’t reassigned in the scope or passed by mutable reference (or indeed are but aren’t actually modified by those functions anyway if the compiler can prove it). My phrasing was probably a bit ambiguous there.