Extract utility functions to utils.rs

Author: Y-Nak

clippy_lints/src/unit_types/mod.rs

@@ -1,9 +1,10 @@
+mod utils;
+
 use rustc_errors::Applicability;
 use rustc_hir as hir;
 use rustc_hir::{BinOpKind, Block, Expr, ExprKind, MatchSource, Node, Stmt, StmtKind};
 use rustc_lint::{LateContext, LateLintPass, LintContext};
 use rustc_middle::lint::in_external_macro;
-use rustc_middle::ty::{self, Ty};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::hygiene::{ExpnKind, MacroKind};
 
@@ -13,6 +14,8 @@ use crate::utils::diagnostics::{span_lint, span_lint_and_then};
 use crate::utils::higher;
 use crate::utils::source::{indent_of, reindent_multiline, snippet_opt, snippet_with_macro_callsite};
 
+use utils::{is_unit, is_unit_literal};
+
 declare_clippy_lint! {
     /// **What it does:** Checks for binding a unit value.
     ///
@@ -244,14 +247,6 @@ fn is_questionmark_desugar_marked_call(expr: &Expr<'_>) -> bool {
     }
 }
 
-fn is_unit(ty: Ty<'_>) -> bool {
-    matches!(ty.kind(), ty::Tuple(slice) if slice.is_empty())
-}
-
-fn is_unit_literal(expr: &Expr<'_>) -> bool {
-    matches!(expr.kind, ExprKind::Tup(ref slice) if slice.is_empty())
-}
-
 fn lint_unit_args(cx: &LateContext<'_>, expr: &Expr<'_>, args_to_recover: &[&Expr<'_>]) {
     let mut applicability = Applicability::MachineApplicable;
     let (singular, plural) = if args_to_recover.len() > 1 {

clippy_lints/src/unit_types/utils.rs

@@ -0,0 +1,10 @@
+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())
+}