diff --git a/clippy_lints/src/casts/unnecessary_cast.rs b/clippy_lints/src/casts/unnecessary_cast.rs index fa2a07ef1da..c43bbf32949 100644 --- a/clippy_lints/src/casts/unnecessary_cast.rs +++ b/clippy_lints/src/casts/unnecessary_cast.rs @@ -7,7 +7,7 @@ use rustc_middle::ty::{self, FloatTy, InferTy, Ty}; use if_chain::if_chain; -use crate::utils::{numeric_literal::NumericLiteral, snippet_opt, span_lint, span_lint_and_sugg}; +use crate::utils::{numeric_literal::NumericLiteral, snippet_opt, span_lint_and_sugg}; use super::UNNECESSARY_CAST; @@ -44,9 +44,18 @@ pub(super) fn check( lint_unnecessary_cast(cx, expr, &literal_str, cast_from, cast_to); }, LitKind::Int(_, LitIntType::Unsuffixed) | LitKind::Float(_, LitFloatType::Unsuffixed) => {}, + LitKind::Int(_, LitIntType::Signed(_) | LitIntType::Unsigned(_)) + | LitKind::Float(_, LitFloatType::Suffixed(_)) + if cast_from.kind() == cast_to.kind() => + { + if let Some(src) = snippet_opt(cx, lit.span) { + let num_lit = NumericLiteral::from_lit_kind(&src, &lit.node).unwrap(); + lint_unnecessary_cast(cx, expr, num_lit.integer, cast_from, cast_to); + } + }, _ => { if cast_from.kind() == cast_to.kind() && !in_external_macro(cx.sess(), expr.span) { - span_lint( + span_lint_and_sugg( cx, UNNECESSARY_CAST, expr.span, @@ -54,6 +63,9 @@ pub(super) fn check( "casting to the same type is unnecessary (`{}` -> `{}`)", cast_from, cast_to ), + "try", + literal_str, + Applicability::MachineApplicable, ); return true; } diff --git a/tests/ui/unnecessary_cast.stderr b/tests/ui/unnecessary_cast.stderr index 8981d13e8ea..70aa448af68 100644 --- a/tests/ui/unnecessary_cast.stderr +++ b/tests/ui/unnecessary_cast.stderr @@ -1,22 +1,22 @@ -error: casting to the same type is unnecessary (`i32` -> `i32`) +error: casting integer literal to `i32` is unnecessary --> $DIR/unnecessary_cast.rs:6:5 | LL | 1i32 as i32; - | ^^^^^^^^^^^ + | ^^^^^^^^^^^ help: try: `1_i32` | = note: `-D clippy::unnecessary-cast` implied by `-D warnings` -error: casting to the same type is unnecessary (`f32` -> `f32`) +error: casting float literal to `f32` is unnecessary --> $DIR/unnecessary_cast.rs:7:5 | LL | 1f32 as f32; - | ^^^^^^^^^^^ + | ^^^^^^^^^^^ help: try: `1_f32` error: casting to the same type is unnecessary (`bool` -> `bool`) --> $DIR/unnecessary_cast.rs:8:5 | LL | false as bool; - | ^^^^^^^^^^^^^ + | ^^^^^^^^^^^^^ help: try: `false` error: aborting due to 3 previous errors