Fixing confusion between mod and remainder

compiler/rustc_hir_typeck/src/op.rs

@@ -335,7 +335,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
  format!("cannot divide `{lhs_ty}` by `{rhs_ty}`")
  }
  hir::BinOpKind::Rem => {
- format!("cannot mod `{lhs_ty}` by `{rhs_ty}`")
+ format!(
+ "cannot calculate the remainder of `{lhs_ty}` divided by `{rhs_ty}`"
+ )
  }
  hir::BinOpKind::BitAnd => {
  format!("no implementation for `{lhs_ty} & {rhs_ty}`")

library/core/src/ops/arith.rs

@@ -545,7 +545,7 @@ div_impl_float! { f32 f64 }
 #[lang = "rem"]
 #[stable(feature = "rust1", since = "1.0.0")]
 #[rustc_on_unimplemented(
- message = "cannot mod `{Self}` by `{Rhs}`",
+ message = "cannot calculate the remainder of `{Self}` divided by `{Rhs}`",
  label = "no implementation for `{Self} % {Rhs}`"
 )]
 #[doc(alias = "%")]
@@ -981,7 +981,7 @@ div_assign_impl! { usize u8 u16 u32 u64 u128 isize i8 i16 i32 i64 i128 f32 f64 }
 #[lang = "rem_assign"]
 #[stable(feature = "op_assign_traits", since = "1.8.0")]
 #[rustc_on_unimplemented(
- message = "cannot mod-assign `{Self}` by `{Rhs}``",
+ message = "cannot calculate and assign the remainder of `{Self}` divided by `{Rhs}`",
  label = "no implementation for `{Self} %= {Rhs}`"
 )]
 #[doc(alias = "%")]

tests/ui/binop/binary-op-on-double-ref.fixed

@@ -3,7 +3,7 @@ fn main() {
  let v = vec![1, 2, 3, 4, 5, 6, 7, 8, 9];
  let vr = v.iter().filter(|x| {
  *x % 2 == 0
- //~^ ERROR cannot mod `&&{integer}` by `{integer}`
+ //~^ ERROR cannot calculate the remainder of `&&{integer}` divided by `{integer}`
  });
  println!("{:?}", vr);
 }

tests/ui/binop/binary-op-on-double-ref.rs

@@ -3,7 +3,7 @@ fn main() {
  let v = vec![1, 2, 3, 4, 5, 6, 7, 8, 9];
  let vr = v.iter().filter(|x| {
  x % 2 == 0
- //~^ ERROR cannot mod `&&{integer}` by `{integer}`
+ //~^ ERROR cannot calculate the remainder of `&&{integer}` divided by `{integer}`
  });
  println!("{:?}", vr);
 }

tests/ui/binop/binary-op-on-double-ref.stderr

@@ -1,4 +1,4 @@
-error[E0369]: cannot mod `&&{integer}` by `{integer}`
+error[E0369]: cannot calculate the remainder of `&&{integer}` divided by `{integer}`
  --> $DIR/binary-op-on-double-ref.rs:5:11
  |
 LL | x % 2 == 0

tests/ui/binop/issue-28837.rs

@@ -11,7 +11,7 @@ fn main() {
 
  a / a; //~ ERROR cannot divide `A` by `A`
 
- a % a; //~ ERROR cannot mod `A` by `A`
+ a % a; //~ ERROR cannot calculate the remainder of `A` divided by `A`
 
  a & a; //~ ERROR no implementation for `A & A`
 

tests/ui/binop/issue-28837.stderr

@@ -62,7 +62,7 @@ LL | struct A;
 note: the trait `Div` must be implemented
  --> $SRC_DIR/core/src/ops/arith.rs:LL:COL
 
-error[E0369]: cannot mod `A` by `A`
+error[E0369]: cannot calculate the remainder of `A` divided by `A`
  --> $DIR/issue-28837.rs:14:7
  |
 LL | a % a;