Remove unit_types::utils::is_unit

Author: Y-Nak

clippy_lints/src/unit_types/let_unit_value.rs

@@ -6,11 +6,11 @@ use rustc_middle::lint::in_external_macro;
 use crate::utils::source::snippet_with_macro_callsite;
 use crate::utils::{higher, span_lint_and_then};
 
-use super::{utils, LET_UNIT_VALUE};
+use super::LET_UNIT_VALUE;
 
 pub(super) fn check(cx: &LateContext<'_>, stmt: &Stmt<'_>) {
     if let StmtKind::Local(ref local) = stmt.kind {
-        if utils::is_unit(cx.typeck_results().pat_ty(&local.pat)) {
+        if cx.typeck_results().pat_ty(&local.pat).is_unit() {
             if in_external_macro(cx.sess(), stmt.span) || local.pat.span.from_expansion() {
                 return;
             }

clippy_lints/src/unit_types/unit_arg.rs

@@ -36,7 +36,7 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>) {
             let args_to_recover = args
                 .iter()
                 .filter(|arg| {
-                    if utils::is_unit(cx.typeck_results().expr_ty(arg)) && !utils::is_unit_literal(arg) {
+                    if cx.typeck_results().expr_ty(arg).is_unit() && !utils::is_unit_literal(arg) {
                         !matches!(
                             &arg.kind,
                             ExprKind::Match(.., MatchSource::TryDesugar) | ExprKind::Path(..)

clippy_lints/src/unit_types/unit_cmp.rs

@@ -4,15 +4,15 @@ use rustc_span::hygiene::{ExpnKind, MacroKind};
 
 use crate::utils::span_lint;
 
-use super::{utils, UNIT_CMP};
+use super::UNIT_CMP;
 
 pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>) {
     if expr.span.from_expansion() {
         if let Some(callee) = expr.span.source_callee() {
             if let ExpnKind::Macro(MacroKind::Bang, symbol) = callee.kind {
                 if let ExprKind::Binary(ref cmp, ref left, _) = expr.kind {
                     let op = cmp.node;
-                    if op.is_comparison() && utils::is_unit(cx.typeck_results().expr_ty(left)) {
+                    if op.is_comparison() && cx.typeck_results().expr_ty(left).is_unit() {
                         let result = match &*symbol.as_str() {
                             "assert_eq" | "debug_assert_eq" => "succeed",
                             "assert_ne" | "debug_assert_ne" => "fail",
@@ -37,7 +37,7 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>) {
 
     if let ExprKind::Binary(ref cmp, ref left, _) = expr.kind {
         let op = cmp.node;
-        if op.is_comparison() && utils::is_unit(cx.typeck_results().expr_ty(left)) {
+        if op.is_comparison() && cx.typeck_results().expr_ty(left).is_unit() {
             let result = match op {
                 BinOpKind::Eq | BinOpKind::Le | BinOpKind::Ge => "true",
                 _ => "false",

clippy_lints/src/unit_types/utils.rs

@@ -1,9 +1,4 @@
 use rustc_hir::{Expr, ExprKind};
-use rustc_middle::ty::{self, Ty};
-
-pub(super) fn is_unit(ty: Ty<'_>) -> bool {
-    matches!(ty.kind(), ty::Tuple(slice) if slice.is_empty())
-}
 
 pub(super) fn is_unit_literal(expr: &Expr<'_>) -> bool {
     matches!(expr.kind, ExprKind::Tup(ref slice) if slice.is_empty())