Function clippy_utils::pat_and_expr_can_be_question_mark
source · pub fn pat_and_expr_can_be_question_mark<'a, 'hir>(
cx: &LateContext<'_>,
pat: &'a Pat<'hir>,
else_body: &Expr<'_>
) -> Option<&'a Pat<'hir>>
Expand description
Returns whether the given let pattern and else body can be turned into a question mark
For this example:
ⓘ
let FooBar { a, b } = if let Some(a) = ex { a } else { return None };
We get as parameters:
ⓘ
pat: Some(a)
else_body: return None
And for this example:
ⓘ
let Some(FooBar { a, b }) = ex else { return None };
We get as parameters:
ⓘ
pat: Some(FooBar { a, b })
else_body: return None
We output Some(a)
in the first instance, and Some(FooBar { a, b })
in the second, because
the question mark operator is applicable here. Callers have to check whether we are in a
constant or not.