Macro all

macro_rules! all {
    () => { ... };
    ($L:ty $(, $R:ty)*) => { ... };
    ({ $L:expr } $(, { $R:expr })*) => { ... };
}

Helper macro to compute whether

• all of a list of types, all implementing crate::TypeLayout, e.g. [T, U, V],
• all of a list of braced expressions of type crate::MaybeUninhabited, e.g. [{ all![] }, { any![] }, { all![] }],

are inhabited.

all![] resolves to crate::MaybeUninhabited::Inhabited.

For instance, a struct is inhabited iff all of its fields are inhabited. The empty list of types is inhabited. This macro resolves into either crate::MaybeUninhabited::Inhabited or crate::MaybeUninhabited::Uninhabited.