Trait rustc_lint::unused::UnusedDelimLint
source · trait UnusedDelimLint {
const DELIM_STR: &'static str;
const LINT_EXPR_IN_PATTERN_MATCHING_CTX: bool;
// Required methods
fn lint(&self) -> &'static Lint;
fn check_unused_delims_expr(
&self,
cx: &EarlyContext<'_>,
value: &Expr,
ctx: UnusedDelimsCtx,
followed_by_block: bool,
left_pos: Option<BytePos>,
right_pos: Option<BytePos>,
is_kw: bool
);
// Provided methods
fn is_expr_delims_necessary(
inner: &Expr,
followed_by_block: bool,
followed_by_else: bool
) -> bool { ... }
fn emit_unused_delims_expr(
&self,
cx: &EarlyContext<'_>,
value: &Expr,
ctx: UnusedDelimsCtx,
left_pos: Option<BytePos>,
right_pos: Option<BytePos>,
is_kw: bool
) { ... }
fn emit_unused_delims(
&self,
cx: &EarlyContext<'_>,
value_span: Span,
spans: Option<(Span, Span)>,
msg: &str,
keep_space: (bool, bool),
is_kw: bool
) { ... }
fn check_expr(&mut self, cx: &EarlyContext<'_>, e: &Expr) { ... }
fn check_stmt(&mut self, cx: &EarlyContext<'_>, s: &Stmt) { ... }
fn check_item(&mut self, cx: &EarlyContext<'_>, item: &Item) { ... }
}Expand description
Used by both UnusedParens and UnusedBraces to prevent code duplication.
Required Associated Constants§
const DELIM_STR: &'static str
sourceconst LINT_EXPR_IN_PATTERN_MATCHING_CTX: bool
const LINT_EXPR_IN_PATTERN_MATCHING_CTX: bool
Due to ref pattern, there can be a difference between using
{ expr } and expr in pattern-matching contexts. This means
that we should only lint unused_parens and not unused_braces
in this case.
let mut a = 7;
let ref b = { a }; // We actually borrow a copy of `a` here.
a += 1; // By mutating `a` we invalidate any borrows of `a`.
assert_eq!(b + 1, a); // `b` does not borrow `a`, so we can still use it here.