Macro any

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

Helper macro to compute whether

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

is inhabited.

any![] resolves to crate::MaybeUninhabited::Uninhabited.

For instance, an enum is inhabited iff any of its variants is inhabited. The empty list of types is uninhabited. This macro resolves into either crate::MaybeUninhabited::Inhabited or crate::MaybeUninhabited::Uninhabited.