Implement review suggestions

clippy_lints/src/loops.rs

@@ -27,7 +27,7 @@
 use rustc_middle::ty::{self, Ty, TyS};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::source_map::Span;
-use rustc_span::symbol::{Ident, Symbol};
+use rustc_span::symbol::{sym, Ident, Symbol};
 use rustc_typeck::expr_use_visitor::{ConsumeMode, Delegate, ExprUseVisitor, PlaceBase, PlaceWithHirId};
 use std::iter::{once, Iterator};
 use std::mem;
@@ -2442,7 +2442,7 @@ fn check_needless_collect_indirect_usage<'tcx>(expr: &'tcx Expr<'_>, cx: &LateCo
                 if let Some(ref generic_args) = method_name.args;
                 if let Some(GenericArg::Type(ref ty)) = generic_args.args.get(0);
                 if let ty = cx.typeck_results().node_type(ty.hir_id);
-                if is_type_diagnostic_item(cx, ty, sym!(vec_type)) ||
+                if is_type_diagnostic_item(cx, ty, sym::vec_type) ||
                     is_type_diagnostic_item(cx, ty, sym!(vecdeque_type)) ||
                     match_type(cx, ty, &paths::LINKED_LIST);
                 if let Some(iter_calls) = detect_iter_and_into_iters(block, *ident);
@@ -2524,12 +2524,11 @@ fn visit_expr(&mut self, expr: &'tcx Expr<'tcx>) {
             if let &[name] = &path.segments;
             if name.ident == self.target;
             then {
-                let into_iter = sym!(into_iter);
                 let len = sym!(len);
                 let is_empty = sym!(is_empty);
                 let contains = sym!(contains);
                 match method_name.ident.name {
-                    name if name == into_iter => self.uses.push(
+                    sym::into_iter => self.uses.push(
                         IterFunction { func: IterFunctionKind::IntoIter, span: expr.span }
                     ),
                     name if name == len => self.uses.push(

tests/ui/needless_collect_indirect.fixed

@@ -1,22 +0,0 @@
-// run-rustfix
-
-#[allow(unused)]
-use std::collections::{HashMap, VecDeque};
-
-fn main() {
-    let sample = [1; 5];
-    let indirect_iter = sample.iter().collect::<Vec<_>>();
-    indirect_iter.into_iter().map(|x| (x, x + 1)).collect::<HashMap<_, _>>();
-    let indirect_len = sample.iter().collect::<VecDeque<_>>();
-    indirect_len.len();
-    let indirect_empty = sample.iter().collect::<VecDeque<_>>();
-    indirect_empty.is_empty();
-    let indirect_contains = sample.iter().collect::<VecDeque<_>>();
-    indirect_contains.contains(&&5);
-    let indirect_negative = sample.iter().collect::<Vec<_>>();
-    indirect_negative.len();
-    indirect_negative
-        .into_iter()
-        .map(|x| (*x, *x + 1))
-        .collect::<HashMap<_, _>>();
-}

tests/ui/needless_collect_indirect.rs

@@ -1,6 +1,3 @@
-// run-rustfix
-
-#[allow(unused)]
 use std::collections::{HashMap, VecDeque};
 
 fn main() {

tests/ui/needless_collect_indirect.stderr

@@ -1,5 +1,5 @@
 error: avoid using `collect()` when not needed
-  --> $DIR/needless_collect_indirect.rs:8:5
+  --> $DIR/needless_collect_indirect.rs:5:5
    |
 LL | /     let indirect_iter = sample.iter().collect::<Vec<_>>();
 LL | |     indirect_iter.into_iter().map(|x| (x, x + 1)).collect::<HashMap<_, _>>();
@@ -13,7 +13,7 @@ LL |     sample.iter().map(|x| (x, x + 1)).collect::<HashMap<_, _>>();
    |
 
 error: avoid using `collect()` when not needed
-  --> $DIR/needless_collect_indirect.rs:10:5
+  --> $DIR/needless_collect_indirect.rs:7:5
    |
 LL | /     let indirect_len = sample.iter().collect::<VecDeque<_>>();
 LL | |     indirect_len.len();
@@ -26,7 +26,7 @@ LL |     sample.iter().count();
    |
 
 error: avoid using `collect()` when not needed
-  --> $DIR/needless_collect_indirect.rs:12:5
+  --> $DIR/needless_collect_indirect.rs:9:5
    |
 LL | /     let indirect_empty = sample.iter().collect::<VecDeque<_>>();
 LL | |     indirect_empty.is_empty();
@@ -39,7 +39,7 @@ LL |     sample.iter().next().is_none();
    |
 
 error: avoid using `collect()` when not needed
-  --> $DIR/needless_collect_indirect.rs:14:5
+  --> $DIR/needless_collect_indirect.rs:11:5
    |
 LL | /     let indirect_contains = sample.iter().collect::<VecDeque<_>>();
 LL | |     indirect_contains.contains(&&5);