Enum Needs 

#[repr(u32)]
pub enum Needs {
    Nothing = 0,
    Upstream = 4,
    Downstream = 8,
    Both = 12,
}

What a stage needs of the path it is placed on.

Read once, out of bits 2 and 3 of tocat_boundaries. Unlike Boundaries, which the host only warns about, an unmet requirement is a configuration error: a stage saying this cannot do its job at all.

The two sides are separate because the stages that want them want opposite ones. A stage that seals a message and appends a tag makes its own boundaries and needs them to survive downwards; the stage that verifies and strips that tag needs whole messages from above and does not care what happens below it.

Variants

Nothing = 0

Upstream = 4

Downstream = 8

Both = 12

Implementations

impl Needs

pub const fn from_u32(value: u32) -> Option<Needs>

pub const fn as_u32(self) -> u32

pub const fn upstream(self) -> bool

pub const fn downstream(self) -> bool

Trait Implementations

impl Clone for Needs

fn clone(&self) -> Needs

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for Needs

impl Debug for Needs

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Default for Needs

fn default() -> Needs

Returns the “default value” for a type.

impl Eq for Needs

impl PartialEq for Needs

fn eq(&self, other: &Needs) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for Needs