Struct QueryOne 

pub struct QueryOne<'w, Q: Query> {
    row: usize,
    plan: Q::Plan<'w>,
    _claims: Claims<'w>,
    marker: PhantomData<fn() -> Q>,
}

What a scope hands out for a query over one entity.

Made by crate::Scope::query_one, which claims the components the query reaches on that entity’s row. A missing match is still answered with an error rather than a holder, so a caller that finds nothing holds no claim.

QueryOne::get is what reads the row, and it takes the holder exclusively: an exclusive item borrows from the call, so the compiler refuses a second one while the first is alive.

Fields

row: usize

plan: Q::Plan<'w>

_claims: Claims<'w>

Held for the life of the holder: dropping it is what releases the claim.

marker: PhantomData<fn() -> Q>

Implementations

impl<'w, Q: Query> QueryOne<'w, Q>

pub(crate) fn new(plan: Q::Plan<'w>, row: usize, claims: Claims<'w>) -> Self

pub fn get(&mut self) -> Q::Item<'_>

What the query yields for this entity’s row.

Trait Implementations

impl<Q: Query> Debug for QueryOne<'_, Q>

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

Formats the value using the given formatter.