rust/clippy_lints/src/methods/iter_cloned_collect.rs
2021-11-28 23:59:31 +09:00

32 lines
1.1 KiB
Rust

use crate::methods::utils::derefs_to_slice;
use clippy_utils::diagnostics::span_lint_and_sugg;
use clippy_utils::ty::is_type_diagnostic_item;
use if_chain::if_chain;
use rustc_errors::Applicability;
use rustc_hir as hir;
use rustc_lint::LateContext;
use rustc_span::sym;
use super::ITER_CLONED_COLLECT;
pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, method_name: &str, expr: &hir::Expr<'_>, recv: &'tcx hir::Expr<'_>) {
if_chain! {
if is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(expr), sym::Vec);
if let Some(slice) = derefs_to_slice(cx, recv, cx.typeck_results().expr_ty(recv));
if let Some(to_replace) = expr.span.trim_start(slice.span.source_callsite());
then {
span_lint_and_sugg(
cx,
ITER_CLONED_COLLECT,
to_replace,
&format!("called `iter().{}().collect()` on a slice to create a `Vec`. Calling `to_vec()` is both faster and \
more readable", method_name),
"try",
".to_vec()".to_string(),
Applicability::MachineApplicable,
);
}
}
}