Function rustc_abi::layout::univariant

fn univariant(
    this: &impl LayoutCalculator + ?Sized,
    dl: &TargetDataLayout,
    fields: &IndexSlice<FieldIdx, Layout<'_>>,
    repr: &ReprOptions,
    kind: StructKind,
    niche_bias: NicheBias
) -> Option<LayoutS>