diff options
Diffstat (limited to 'src/tools/clippy/clippy_lints/src/casts/mod.rs')
| -rw-r--r-- | src/tools/clippy/clippy_lints/src/casts/mod.rs | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/src/tools/clippy/clippy_lints/src/casts/mod.rs b/src/tools/clippy/clippy_lints/src/casts/mod.rs index 161e3a698..362f70d12 100644 --- a/src/tools/clippy/clippy_lints/src/casts/mod.rs +++ b/src/tools/clippy/clippy_lints/src/casts/mod.rs @@ -80,7 +80,8 @@ declare_clippy_lint! { /// ### What it does /// Checks for casts between numerical types that may /// truncate large values. This is expected behavior, so the cast is `Allow` by - /// default. + /// default. It suggests user either explicitly ignore the lint, + /// or use `try_from()` and handle the truncation, default, or panic explicitly. /// /// ### Why is this bad? /// In some problem domains, it is good practice to avoid @@ -93,6 +94,21 @@ declare_clippy_lint! { /// x as u8 /// } /// ``` + /// Use instead: + /// ``` + /// fn as_u8(x: u64) -> u8 { + /// if let Ok(x) = u8::try_from(x) { + /// x + /// } else { + /// todo!(); + /// } + /// } + /// // Or + /// #[allow(clippy::cast_possible_truncation)] + /// fn as_u16(x: u64) -> u16 { + /// x as u16 + /// } + /// ``` #[clippy::version = "pre 1.29.0"] pub CAST_POSSIBLE_TRUNCATION, pedantic, @@ -712,7 +728,7 @@ impl<'tcx> LateLintPass<'tcx> for Casts { fn_to_numeric_cast_with_truncation::check(cx, expr, cast_expr, cast_from, cast_to); if cast_to.is_numeric() && !in_external_macro(cx.sess(), expr.span) { - cast_possible_truncation::check(cx, expr, cast_expr, cast_from, cast_to); + cast_possible_truncation::check(cx, expr, cast_expr, cast_from, cast_to, cast_to_hir.span); if cast_from.is_numeric() { cast_possible_wrap::check(cx, expr, cast_from, cast_to); cast_precision_loss::check(cx, expr, cast_from, cast_to); |