Auto merge of #12722 - MATSMACKE:master, r=Alexendoo

Fix false positive in `cast_possible_truncation`

Fixes [#12721](https://github.com/rust-lang/rust-clippy/issues/12721)

changelog: [`cast_possible_truncation`]:  Separated checking whether integer constant has sufficient leading zeroes to be safely casted when getting remainder from bitwise and, since the latter allows a constant on either side of the operator to increase the number of leading zeroes that can be guaranteed.

3 files changed, 141 insertions, 93 deletions

diff --git a/clippy_lints/src/casts/cast_possible_truncation.rs b/clippy_lints/src/casts/cast_possible_truncation.rs
index dbfa8e1ee91..7c5acd1a678 100644
--- a/clippy_lints/src/casts/cast_possible_truncation.rs
+++ b/clippy_lints/src/casts/cast_possible_truncation.rs
@@ -40,9 +40,14 @@ fn apply_reductions(cx: &LateContext<'_>, nbits: u64, expr: &Expr<'_>, signed: b
                     get_constant_bits(cx, right).map_or(0, |b| b.saturating_sub(1))
                 })
             },
-            BinOpKind::Rem | BinOpKind::BitAnd => get_constant_bits(cx, right)
+            BinOpKind::Rem => get_constant_bits(cx, right)
                 .unwrap_or(u64::MAX)
                 .min(apply_reductions(cx, nbits, left, signed)),
+            BinOpKind::BitAnd => get_constant_bits(cx, right)
+                .unwrap_or(u64::MAX)
+                .min(get_constant_bits(cx, left).unwrap_or(u64::MAX))
+                .min(apply_reductions(cx, nbits, right, signed))
+                .min(apply_reductions(cx, nbits, left, signed)),
             BinOpKind::Shr => apply_reductions(cx, nbits, left, signed)
                 .saturating_sub(constant_int(cx, right).map_or(0, |s| u64::try_from(s).unwrap_or_default())),
             _ => nbits,
diff --git a/tests/ui/cast.rs b/tests/ui/cast.rs
index 215c008902d..453d62ce607 100644
--- a/tests/ui/cast.rs
+++ b/tests/ui/cast.rs
@@ -13,7 +13,8 @@
     clippy::cast_abs_to_unsigned,
     clippy::no_effect,
     clippy::unnecessary_operation,
-    clippy::unnecessary_literal_unwrap
+    clippy::unnecessary_literal_unwrap,
+    clippy::identity_op
 )]
 
 fn main() {
@@ -479,3 +480,21 @@ fn issue12506() -> usize {
     let bar: Result<Option<i64>, u32> = Ok(Some(10));
     bar.unwrap().unwrap() as usize
 }
+
+fn issue12721() {
+    fn x() -> u64 {
+        u64::MAX
+    }
+
+    // Don't lint.
+    (255 & 999999u64) as u8;
+    // Don't lint.
+    let _ = ((x() & 255) & 999999) as u8;
+    // Don't lint.
+    let _ = (999999 & (x() & 255)) as u8;
+
+    (256 & 999999u64) as u8;
+    //~^ ERROR: casting `u64` to `u8` may truncate the value
+    (255 % 999999u64) as u8;
+    //~^ ERROR: casting `u64` to `u8` may truncate the value
+}
diff --git a/tests/ui/cast.stderr b/tests/ui/cast.stderr
index 8b269c47176..43c0d8f4ed7 100644
--- a/tests/ui/cast.stderr
+++ b/tests/ui/cast.stderr
@@ -1,5 +1,5 @@
 error: casting `i32` to `f32` causes a loss of precision (`i32` is 32 bits wide, but `f32`'s mantissa is only 23 bits wide)
-  --> tests/ui/cast.rs:22:5
+  --> tests/ui/cast.rs:23:5
    |
 LL |     x0 as f32;
    |     ^^^^^^^^^
@@ -8,37 +8,37 @@ LL |     x0 as f32;
    = help: to override `-D warnings` add `#[allow(clippy::cast_precision_loss)]`
 
 error: casting `i64` to `f32` causes a loss of precision (`i64` is 64 bits wide, but `f32`'s mantissa is only 23 bits wide)
-  --> tests/ui/cast.rs:26:5
+  --> tests/ui/cast.rs:27:5
    |
 LL |     x1 as f32;
    |     ^^^^^^^^^
 
 error: casting `i64` to `f64` causes a loss of precision (`i64` is 64 bits wide, but `f64`'s mantissa is only 52 bits wide)
-  --> tests/ui/cast.rs:28:5
+  --> tests/ui/cast.rs:29:5
    |
 LL |     x1 as f64;
    |     ^^^^^^^^^
 
 error: casting `u32` to `f32` causes a loss of precision (`u32` is 32 bits wide, but `f32`'s mantissa is only 23 bits wide)
-  --> tests/ui/cast.rs:31:5
+  --> tests/ui/cast.rs:32:5
    |
 LL |     x2 as f32;
    |     ^^^^^^^^^
 
 error: casting `u64` to `f32` causes a loss of precision (`u64` is 64 bits wide, but `f32`'s mantissa is only 23 bits wide)
-  --> tests/ui/cast.rs:34:5
+  --> tests/ui/cast.rs:35:5
    |
 LL |     x3 as f32;
    |     ^^^^^^^^^
 
 error: casting `u64` to `f64` causes a loss of precision (`u64` is 64 bits wide, but `f64`'s mantissa is only 52 bits wide)
-  --> tests/ui/cast.rs:36:5
+  --> tests/ui/cast.rs:37:5
    |
 LL |     x3 as f64;
    |     ^^^^^^^^^
 
 error: casting `f32` to `i32` may truncate the value
-  --> tests/ui/cast.rs:39:5
+  --> tests/ui/cast.rs:40:5
    |
 LL |     1f32 as i32;
    |     ^^^^^^^^^^^
@@ -48,7 +48,7 @@ LL |     1f32 as i32;
    = help: to override `-D warnings` add `#[allow(clippy::cast_possible_truncation)]`
 
 error: casting `f32` to `u32` may truncate the value
-  --> tests/ui/cast.rs:41:5
+  --> tests/ui/cast.rs:42:5
    |
 LL |     1f32 as u32;
    |     ^^^^^^^^^^^
@@ -56,7 +56,7 @@ LL |     1f32 as u32;
    = help: if this is intentional allow the lint with `#[allow(clippy::cast_possible_truncation)]` ...
 
 error: casting `f32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:41:5
+  --> tests/ui/cast.rs:42:5
    |
 LL |     1f32 as u32;
    |     ^^^^^^^^^^^
@@ -65,7 +65,7 @@ LL |     1f32 as u32;
    = help: to override `-D warnings` add `#[allow(clippy::cast_sign_loss)]`
 
 error: casting `f64` to `f32` may truncate the value
-  --> tests/ui/cast.rs:45:5
+  --> tests/ui/cast.rs:46:5
    |
 LL |     1f64 as f32;
    |     ^^^^^^^^^^^
@@ -73,7 +73,7 @@ LL |     1f64 as f32;
    = help: if this is intentional allow the lint with `#[allow(clippy::cast_possible_truncation)]` ...
 
 error: casting `i32` to `i8` may truncate the value
-  --> tests/ui/cast.rs:47:5
+  --> tests/ui/cast.rs:48:5
    |
 LL |     1i32 as i8;
    |     ^^^^^^^^^^
@@ -85,7 +85,7 @@ LL |     i8::try_from(1i32);
    |     ~~~~~~~~~~~~~~~~~~
 
 error: casting `i32` to `u8` may truncate the value
-  --> tests/ui/cast.rs:49:5
+  --> tests/ui/cast.rs:50:5
    |
 LL |     1i32 as u8;
    |     ^^^^^^^^^^
@@ -97,7 +97,7 @@ LL |     u8::try_from(1i32);
    |     ~~~~~~~~~~~~~~~~~~
 
 error: casting `f64` to `isize` may truncate the value
-  --> tests/ui/cast.rs:51:5
+  --> tests/ui/cast.rs:52:5
    |
 LL |     1f64 as isize;
    |     ^^^^^^^^^^^^^
@@ -105,7 +105,7 @@ LL |     1f64 as isize;
    = help: if this is intentional allow the lint with `#[allow(clippy::cast_possible_truncation)]` ...
 
 error: casting `f64` to `usize` may truncate the value
-  --> tests/ui/cast.rs:53:5
+  --> tests/ui/cast.rs:54:5
    |
 LL |     1f64 as usize;
    |     ^^^^^^^^^^^^^
@@ -113,13 +113,13 @@ LL |     1f64 as usize;
    = help: if this is intentional allow the lint with `#[allow(clippy::cast_possible_truncation)]` ...
 
 error: casting `f64` to `usize` may lose the sign of the value
-  --> tests/ui/cast.rs:53:5
+  --> tests/ui/cast.rs:54:5
    |
 LL |     1f64 as usize;
    |     ^^^^^^^^^^^^^
 
 error: casting `u32` to `u16` may truncate the value
-  --> tests/ui/cast.rs:56:5
+  --> tests/ui/cast.rs:57:5
    |
 LL |     1f32 as u32 as u16;
    |     ^^^^^^^^^^^^^^^^^^
@@ -131,7 +131,7 @@ LL |     u16::try_from(1f32 as u32);
    |     ~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 error: casting `f32` to `u32` may truncate the value
-  --> tests/ui/cast.rs:56:5
+  --> tests/ui/cast.rs:57:5
    |
 LL |     1f32 as u32 as u16;
    |     ^^^^^^^^^^^
@@ -139,13 +139,13 @@ LL |     1f32 as u32 as u16;
    = help: if this is intentional allow the lint with `#[allow(clippy::cast_possible_truncation)]` ...
 
 error: casting `f32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:56:5
+  --> tests/ui/cast.rs:57:5
    |
 LL |     1f32 as u32 as u16;
    |     ^^^^^^^^^^^
 
 error: casting `i32` to `i8` may truncate the value
-  --> tests/ui/cast.rs:61:22
+  --> tests/ui/cast.rs:62:22
    |
 LL |         let _x: i8 = 1i32 as _;
    |                      ^^^^^^^^^
@@ -157,7 +157,7 @@ LL |         let _x: i8 = 1i32.try_into();
    |                      ~~~~~~~~~~~~~~~
 
 error: casting `f32` to `i32` may truncate the value
-  --> tests/ui/cast.rs:63:9
+  --> tests/ui/cast.rs:64:9
    |
 LL |         1f32 as i32;
    |         ^^^^^^^^^^^
@@ -165,7 +165,7 @@ LL |         1f32 as i32;
    = help: if this is intentional allow the lint with `#[allow(clippy::cast_possible_truncation)]` ...
 
 error: casting `f64` to `i32` may truncate the value
-  --> tests/ui/cast.rs:65:9
+  --> tests/ui/cast.rs:66:9
    |
 LL |         1f64 as i32;
    |         ^^^^^^^^^^^
@@ -173,7 +173,7 @@ LL |         1f64 as i32;
    = help: if this is intentional allow the lint with `#[allow(clippy::cast_possible_truncation)]` ...
 
 error: casting `f32` to `u8` may truncate the value
-  --> tests/ui/cast.rs:67:9
+  --> tests/ui/cast.rs:68:9
    |
 LL |         1f32 as u8;
    |         ^^^^^^^^^^
@@ -181,13 +181,13 @@ LL |         1f32 as u8;
    = help: if this is intentional allow the lint with `#[allow(clippy::cast_possible_truncation)]` ...
 
 error: casting `f32` to `u8` may lose the sign of the value
-  --> tests/ui/cast.rs:67:9
+  --> tests/ui/cast.rs:68:9
    |
 LL |         1f32 as u8;
    |         ^^^^^^^^^^
 
 error: casting `u8` to `i8` may wrap around the value
-  --> tests/ui/cast.rs:72:5
+  --> tests/ui/cast.rs:73:5
    |
 LL |     1u8 as i8;
    |     ^^^^^^^^^
@@ -196,31 +196,31 @@ LL |     1u8 as i8;
    = help: to override `-D warnings` add `#[allow(clippy::cast_possible_wrap)]`
 
 error: casting `u16` to `i16` may wrap around the value
-  --> tests/ui/cast.rs:75:5
+  --> tests/ui/cast.rs:76:5
    |
 LL |     1u16 as i16;
    |     ^^^^^^^^^^^
 
 error: casting `u32` to `i32` may wrap around the value
-  --> tests/ui/cast.rs:77:5
+  --> tests/ui/cast.rs:78:5
    |
 LL |     1u32 as i32;
    |     ^^^^^^^^^^^
 
 error: casting `u64` to `i64` may wrap around the value
-  --> tests/ui/cast.rs:79:5
+  --> tests/ui/cast.rs:80:5
    |
 LL |     1u64 as i64;
    |     ^^^^^^^^^^^
 
 error: casting `usize` to `isize` may wrap around the value
-  --> tests/ui/cast.rs:81:5
+  --> tests/ui/cast.rs:82:5
    |
 LL |     1usize as isize;
    |     ^^^^^^^^^^^^^^^
 
 error: casting `usize` to `i8` may truncate the value
-  --> tests/ui/cast.rs:84:5
+  --> tests/ui/cast.rs:85:5
    |
 LL |     1usize as i8;
    |     ^^^^^^^^^^^^
@@ -232,7 +232,7 @@ LL |     i8::try_from(1usize);
    |     ~~~~~~~~~~~~~~~~~~~~
 
 error: casting `usize` to `i16` may truncate the value
-  --> tests/ui/cast.rs:87:5
+  --> tests/ui/cast.rs:88:5
    |
 LL |     1usize as i16;
    |     ^^^^^^^^^^^^^
@@ -244,7 +244,7 @@ LL |     i16::try_from(1usize);
    |     ~~~~~~~~~~~~~~~~~~~~~
 
 error: casting `usize` to `i16` may wrap around the value on targets with 16-bit wide pointers
-  --> tests/ui/cast.rs:87:5
+  --> tests/ui/cast.rs:88:5
    |
 LL |     1usize as i16;
    |     ^^^^^^^^^^^^^
@@ -253,7 +253,7 @@ LL |     1usize as i16;
    = note: for more information see https://doc.rust-lang.org/reference/types/numeric.html#machine-dependent-integer-types
 
 error: casting `usize` to `i32` may truncate the value on targets with 64-bit wide pointers
-  --> tests/ui/cast.rs:92:5
+  --> tests/ui/cast.rs:93:5
    |
 LL |     1usize as i32;
    |     ^^^^^^^^^^^^^
@@ -265,19 +265,19 @@ LL |     i32::try_from(1usize);
    |     ~~~~~~~~~~~~~~~~~~~~~
 
 error: casting `usize` to `i32` may wrap around the value on targets with 32-bit wide pointers
-  --> tests/ui/cast.rs:92:5
+  --> tests/ui/cast.rs:93:5
    |
 LL |     1usize as i32;
    |     ^^^^^^^^^^^^^
 
 error: casting `usize` to `i64` may wrap around the value on targets with 64-bit wide pointers
-  --> tests/ui/cast.rs:96:5
+  --> tests/ui/cast.rs:97:5
    |
 LL |     1usize as i64;
    |     ^^^^^^^^^^^^^
 
 error: casting `u16` to `isize` may wrap around the value on targets with 16-bit wide pointers
-  --> tests/ui/cast.rs:101:5
+  --> tests/ui/cast.rs:102:5
    |
 LL |     1u16 as isize;
    |     ^^^^^^^^^^^^^
@@ -286,13 +286,13 @@ LL |     1u16 as isize;
    = note: for more information see https://doc.rust-lang.org/reference/types/numeric.html#machine-dependent-integer-types
 
 error: casting `u32` to `isize` may wrap around the value on targets with 32-bit wide pointers
-  --> tests/ui/cast.rs:105:5
+  --> tests/ui/cast.rs:106:5
    |
 LL |     1u32 as isize;
    |     ^^^^^^^^^^^^^
 
 error: casting `u64` to `isize` may truncate the value on targets with 32-bit wide pointers
-  --> tests/ui/cast.rs:108:5
+  --> tests/ui/cast.rs:109:5
    |
 LL |     1u64 as isize;
    |     ^^^^^^^^^^^^^
@@ -304,55 +304,55 @@ LL |     isize::try_from(1u64);
    |     ~~~~~~~~~~~~~~~~~~~~~
 
 error: casting `u64` to `isize` may wrap around the value on targets with 64-bit wide pointers
-  --> tests/ui/cast.rs:108:5
+  --> tests/ui/cast.rs:109:5
    |
 LL |     1u64 as isize;
    |     ^^^^^^^^^^^^^
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:113:5
+  --> tests/ui/cast.rs:114:5
    |
 LL |     -1i32 as u32;
    |     ^^^^^^^^^^^^
 
 error: casting `isize` to `usize` may lose the sign of the value
-  --> tests/ui/cast.rs:116:5
+  --> tests/ui/cast.rs:117:5
    |
 LL |     -1isize as usize;
    |     ^^^^^^^^^^^^^^^^
 
 error: casting `i8` to `u8` may lose the sign of the value
-  --> tests/ui/cast.rs:127:5
+  --> tests/ui/cast.rs:128:5
    |
 LL |     (i8::MIN).abs() as u8;
    |     ^^^^^^^^^^^^^^^^^^^^^
 
 error: casting `i64` to `u64` may lose the sign of the value
-  --> tests/ui/cast.rs:131:5
+  --> tests/ui/cast.rs:132:5
    |
 LL |     (-1i64).abs() as u64;
    |     ^^^^^^^^^^^^^^^^^^^^
 
 error: casting `isize` to `usize` may lose the sign of the value
-  --> tests/ui/cast.rs:132:5
+  --> tests/ui/cast.rs:133:5
    |
 LL |     (-1isize).abs() as usize;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: casting `i64` to `u64` may lose the sign of the value
-  --> tests/ui/cast.rs:139:5
+  --> tests/ui/cast.rs:140:5
    |
 LL |     (unsafe { (-1i64).checked_abs().unwrap_unchecked() }) as u64;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: casting `i64` to `u64` may lose the sign of the value
-  --> tests/ui/cast.rs:154:5
+  --> tests/ui/cast.rs:155:5
    |
 LL |     (unsafe { (-1i64).checked_isqrt().unwrap_unchecked() }) as u64;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: casting `i64` to `i8` may truncate the value
-  --> tests/ui/cast.rs:205:5
+  --> tests/ui/cast.rs:206:5
    |
 LL |     (-99999999999i64).min(1) as i8;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -364,7 +364,7 @@ LL |     i8::try_from((-99999999999i64).min(1));
    |     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 error: casting `u64` to `u8` may truncate the value
-  --> tests/ui/cast.rs:219:5
+  --> tests/ui/cast.rs:220:5
    |
 LL |     999999u64.clamp(0, 256) as u8;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -376,7 +376,7 @@ LL |     u8::try_from(999999u64.clamp(0, 256));
    |     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 error: casting `main::E2` to `u8` may truncate the value
-  --> tests/ui/cast.rs:242:21
+  --> tests/ui/cast.rs:243:21
    |
 LL |             let _ = self as u8;
    |                     ^^^^^^^^^^
@@ -388,7 +388,7 @@ LL |             let _ = u8::try_from(self);
    |                     ~~~~~~~~~~~~~~~~~~
 
 error: casting `main::E2::B` to `u8` will truncate the value
-  --> tests/ui/cast.rs:244:21
+  --> tests/ui/cast.rs:245:21
    |
 LL |             let _ = Self::B as u8;
    |                     ^^^^^^^^^^^^^
@@ -397,7 +397,7 @@ LL |             let _ = Self::B as u8;
    = help: to override `-D warnings` add `#[allow(clippy::cast_enum_truncation)]`
 
 error: casting `main::E5` to `i8` may truncate the value
-  --> tests/ui/cast.rs:286:21
+  --> tests/ui/cast.rs:287:21
    |
 LL |             let _ = self as i8;
    |                     ^^^^^^^^^^
@@ -409,13 +409,13 @@ LL |             let _ = i8::try_from(self);
    |                     ~~~~~~~~~~~~~~~~~~
 
 error: casting `main::E5::A` to `i8` will truncate the value
-  --> tests/ui/cast.rs:288:21
+  --> tests/ui/cast.rs:289:21
    |
 LL |             let _ = Self::A as i8;
    |                     ^^^^^^^^^^^^^
 
 error: casting `main::E6` to `i16` may truncate the value
-  --> tests/ui/cast.rs:305:21
+  --> tests/ui/cast.rs:306:21
    |
 LL |             let _ = self as i16;
    |                     ^^^^^^^^^^^
@@ -427,7 +427,7 @@ LL |             let _ = i16::try_from(self);
    |                     ~~~~~~~~~~~~~~~~~~~
 
 error: casting `main::E7` to `usize` may truncate the value on targets with 32-bit wide pointers
-  --> tests/ui/cast.rs:324:21
+  --> tests/ui/cast.rs:325:21
    |
 LL |             let _ = self as usize;
    |                     ^^^^^^^^^^^^^
@@ -439,7 +439,7 @@ LL |             let _ = usize::try_from(self);
    |                     ~~~~~~~~~~~~~~~~~~~~~
 
 error: casting `main::E10` to `u16` may truncate the value
-  --> tests/ui/cast.rs:371:21
+  --> tests/ui/cast.rs:372:21
    |
 LL |             let _ = self as u16;
    |                     ^^^^^^^^^^^
@@ -451,7 +451,7 @@ LL |             let _ = u16::try_from(self);
    |                     ~~~~~~~~~~~~~~~~~~~
 
 error: casting `u32` to `u8` may truncate the value
-  --> tests/ui/cast.rs:382:13
+  --> tests/ui/cast.rs:383:13
    |
 LL |     let c = (q >> 16) as u8;
    |             ^^^^^^^^^^^^^^^
@@ -463,7 +463,7 @@ LL |     let c = u8::try_from(q >> 16);
    |             ~~~~~~~~~~~~~~~~~~~~~
 
 error: casting `u32` to `u8` may truncate the value
-  --> tests/ui/cast.rs:386:13
+  --> tests/ui/cast.rs:387:13
    |
 LL |     let c = (q / 1000) as u8;
    |             ^^^^^^^^^^^^^^^^
@@ -475,85 +475,85 @@ LL |     let c = u8::try_from(q / 1000);
    |             ~~~~~~~~~~~~~~~~~~~~~~
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:398:9
+  --> tests/ui/cast.rs:399:9
    |
 LL |         (x * x) as u32;
    |         ^^^^^^^^^^^^^^
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:403:32
+  --> tests/ui/cast.rs:404:32
    |
 LL |     let _a = |x: i32| -> u32 { (x * x * x * x) as u32 };
    |                                ^^^^^^^^^^^^^^^^^^^^^^
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:405:5
+  --> tests/ui/cast.rs:406:5
    |
 LL |     (2_i32).checked_pow(3).unwrap() as u32;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:406:5
+  --> tests/ui/cast.rs:407:5
    |
 LL |     (-2_i32).pow(3) as u32;
    |     ^^^^^^^^^^^^^^^^^^^^^^
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:411:5
+  --> tests/ui/cast.rs:412:5
    |
 LL |     (-5_i32 % 2) as u32;
    |     ^^^^^^^^^^^^^^^^^^^
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:413:5
+  --> tests/ui/cast.rs:414:5
    |
 LL |     (-5_i32 % -2) as u32;
    |     ^^^^^^^^^^^^^^^^^^^^
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:416:5
+  --> tests/ui/cast.rs:417:5
    |
 LL |     (-2_i32 >> 1) as u32;
    |     ^^^^^^^^^^^^^^^^^^^^
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:420:5
+  --> tests/ui/cast.rs:421:5
    |
 LL |     (x * x) as u32;
    |     ^^^^^^^^^^^^^^
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:421:5
+  --> tests/ui/cast.rs:422:5
    |
 LL |     (x * x * x) as u32;
    |     ^^^^^^^^^^^^^^^^^^
 
 error: casting `i16` to `u16` may lose the sign of the value
-  --> tests/ui/cast.rs:425:5
+  --> tests/ui/cast.rs:426:5
    |
 LL |     (y * y * y * y * -2) as u16;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: casting `i16` to `u16` may lose the sign of the value
-  --> tests/ui/cast.rs:427:5
+  --> tests/ui/cast.rs:428:5
    |
 LL |     (y * y * y / y * 2) as u16;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: casting `i16` to `u16` may lose the sign of the value
-  --> tests/ui/cast.rs:428:5
+  --> tests/ui/cast.rs:429:5
    |
 LL |     (y * y / y * 2) as u16;
    |     ^^^^^^^^^^^^^^^^^^^^^^
 
 error: casting `i16` to `u16` may lose the sign of the value
-  --> tests/ui/cast.rs:430:5
+  --> tests/ui/cast.rs:431:5
    |
 LL |     (y / y * y * -2) as u16;
    |     ^^^^^^^^^^^^^^^^^^^^^^^
 
 error: equal expressions as operands to `/`
-  --> tests/ui/cast.rs:430:6
+  --> tests/ui/cast.rs:431:6
    |
 LL |     (y / y * y * -2) as u16;
    |      ^^^^^
@@ -561,97 +561,97 @@ LL |     (y / y * y * -2) as u16;
    = note: `#[deny(clippy::eq_op)]` on by default
 
 error: casting `i16` to `u16` may lose the sign of the value
-  --> tests/ui/cast.rs:433:5
+  --> tests/ui/cast.rs:434:5
    |
 LL |     (y + y + y + -2) as u16;
    |     ^^^^^^^^^^^^^^^^^^^^^^^
 
 error: casting `i16` to `u16` may lose the sign of the value
-  --> tests/ui/cast.rs:435:5
+  --> tests/ui/cast.rs:436:5
    |
 LL |     (y + y + y + 2) as u16;
    |     ^^^^^^^^^^^^^^^^^^^^^^
 
 error: casting `i16` to `u16` may lose the sign of the value
-  --> tests/ui/cast.rs:439:5
+  --> tests/ui/cast.rs:440:5
    |
 LL |     (z + -2) as u16;
    |     ^^^^^^^^^^^^^^^
 
 error: casting `i16` to `u16` may lose the sign of the value
-  --> tests/ui/cast.rs:441:5
+  --> tests/ui/cast.rs:442:5
    |
 LL |     (z + z + 2) as u16;
    |     ^^^^^^^^^^^^^^^^^^
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:444:9
+  --> tests/ui/cast.rs:445:9
    |
 LL |         (a * a * b * b * c * c) as u32;
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:445:9
+  --> tests/ui/cast.rs:446:9
    |
 LL |         (a * b * c) as u32;
    |         ^^^^^^^^^^^^^^^^^^
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:447:9
+  --> tests/ui/cast.rs:448:9
    |
 LL |         (a * -b * c) as u32;
    |         ^^^^^^^^^^^^^^^^^^^
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:449:9
+  --> tests/ui/cast.rs:450:9
    |
 LL |         (a * b * c * c) as u32;
    |         ^^^^^^^^^^^^^^^^^^^^^^
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:450:9
+  --> tests/ui/cast.rs:451:9
    |
 LL |         (a * -2) as u32;
    |         ^^^^^^^^^^^^^^^
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:452:9
+  --> tests/ui/cast.rs:453:9
    |
 LL |         (a * b * c * -2) as u32;
    |         ^^^^^^^^^^^^^^^^^^^^^^^
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:454:9
+  --> tests/ui/cast.rs:455:9
    |
 LL |         (a / b) as u32;
    |         ^^^^^^^^^^^^^^
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:455:9
+  --> tests/ui/cast.rs:456:9
    |
 LL |         (a / b * c) as u32;
    |         ^^^^^^^^^^^^^^^^^^
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:457:9
+  --> tests/ui/cast.rs:458:9
    |
 LL |         (a / b + b * c) as u32;
    |         ^^^^^^^^^^^^^^^^^^^^^^
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:459:9
+  --> tests/ui/cast.rs:460:9
    |
 LL |         a.saturating_pow(3) as u32;
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:461:9
+  --> tests/ui/cast.rs:462:9
    |
 LL |         (a.abs() * b.pow(2) / c.abs()) as u32
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: casting `i32` to `u32` may lose the sign of the value
-  --> tests/ui/cast.rs:469:21
+  --> tests/ui/cast.rs:470:21
    |
 LL |             let _ = i32::MIN as u32; // cast_sign_loss
    |                     ^^^^^^^^^^^^^^^
@@ -662,7 +662,7 @@ LL |     m!();
    = note: this error originates in the macro `m` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: casting `u32` to `u8` may truncate the value
-  --> tests/ui/cast.rs:470:21
+  --> tests/ui/cast.rs:471:21
    |
 LL |             let _ = u32::MAX as u8; // cast_possible_truncation
    |                     ^^^^^^^^^^^^^^
@@ -678,7 +678,7 @@ LL |             let _ = u8::try_from(u32::MAX); // cast_possible_truncation
    |                     ~~~~~~~~~~~~~~~~~~~~~~
 
 error: casting `f64` to `f32` may truncate the value
-  --> tests/ui/cast.rs:471:21
+  --> tests/ui/cast.rs:472:21
    |
 LL |             let _ = std::f64::consts::PI as f32; // cast_possible_truncation
    |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -690,7 +690,7 @@ LL |     m!();
    = note: this error originates in the macro `m` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: casting `i64` to `usize` may truncate the value on targets with 32-bit wide pointers
-  --> tests/ui/cast.rs:480:5
+  --> tests/ui/cast.rs:481:5
    |
 LL |     bar.unwrap().unwrap() as usize
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -702,10 +702,34 @@ LL |     usize::try_from(bar.unwrap().unwrap())
    |
 
 error: casting `i64` to `usize` may lose the sign of the value
-  --> tests/ui/cast.rs:480:5
+  --> tests/ui/cast.rs:481:5
    |
 LL |     bar.unwrap().unwrap() as usize
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: aborting due to 90 previous errors
+error: casting `u64` to `u8` may truncate the value
+  --> tests/ui/cast.rs:496:5
+   |
+LL |     (256 & 999999u64) as u8;
+   |     ^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: if this is intentional allow the lint with `#[allow(clippy::cast_possible_truncation)]` ...
+help: ... or use `try_from` and handle the error accordingly
+   |
+LL |     u8::try_from(256 & 999999u64);
+   |     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+error: casting `u64` to `u8` may truncate the value
+  --> tests/ui/cast.rs:498:5
+   |
+LL |     (255 % 999999u64) as u8;
+   |     ^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: if this is intentional allow the lint with `#[allow(clippy::cast_possible_truncation)]` ...
+help: ... or use `try_from` and handle the error accordingly
+   |
+LL |     u8::try_from(255 % 999999u64);
+   |     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+error: aborting due to 92 previous errors