feat: omit suffixes in const generics (e.g. 1_i32)

Closes #99255

Author: Logarithmus

compiler/rustc_middle/src/ty/print/pretty.rs

@@ -1727,7 +1727,7 @@ impl<'tcx> Printer<'tcx> for FmtPrinter<'_, 'tcx> {
     }
 
     fn print_const(self, ct: ty::Const<'tcx>) -> Result<Self::Const, Self::Error> {
-        self.pretty_print_const(ct, true)
+        self.pretty_print_const(ct, false)
     }
 
     fn path_crate(mut self, cnum: CrateNum) -> Result<Self::Path, Self::Error> {

src/test/ui/array-slice-vec/match_arr_unknown_len.stderr

@@ -2,7 +2,7 @@ error[E0308]: mismatched types
   --> $DIR/match_arr_unknown_len.rs:3:9
    |
 LL |         [1, 2] => true,
-   |         ^^^^^^ expected `2_usize`, found `N`
+   |         ^^^^^^ expected `2`, found `N`
    |
    = note: expected array `[u32; 2]`
               found array `[u32; N]`

src/test/ui/const-generics/associated-type-bound-fail.stderr

@@ -4,7 +4,7 @@ error[E0277]: the trait bound `u16: Bar<N>` is not satisfied
 LL |     type Assoc = u16;
    |                  ^^^ the trait `Bar<N>` is not implemented for `u16`
    |
-   = help: the trait `Bar<3_usize>` is implemented for `u16`
+   = help: the trait `Bar<3>` is implemented for `u16`
 note: required by a bound in `Foo::Assoc`
   --> $DIR/associated-type-bound-fail.rs:4:17
    |

src/test/ui/const-generics/defaults/generic-expr-default-concrete.stderr

@@ -2,10 +2,10 @@ error[E0308]: mismatched types
   --> $DIR/generic-expr-default-concrete.rs:10:5
    |
 LL |     Foo::<10, 12>
-   |     ^^^^^^^^^^^^^ expected `11_usize`, found `12_usize`
+   |     ^^^^^^^^^^^^^ expected `11`, found `12`
    |
-   = note: expected type `11_usize`
-              found type `12_usize`
+   = note: expected type `11`
+              found type `12`
 
 error: aborting due to previous error
 

src/test/ui/const-generics/defaults/mismatch.rs

@@ -1,22 +1,22 @@
-pub struct Example<const N: usize=13>;
-pub struct Example2<T=u32, const N: usize=13>(T);
-pub struct Example3<const N: usize=13, T=u32>(T);
-pub struct Example4<const N: usize=13, const M: usize=4>;
+pub struct Example<const N: usize = 13>;
+pub struct Example2<T = u32, const N: usize = 13>(T);
+pub struct Example3<const N: usize = 13, T = u32>(T);
+pub struct Example4<const N: usize = 13, const M: usize = 4>;
 
 fn main() {
-    let e: Example::<13> = ();
+    let e: Example<13> = ();
     //~^ Error: mismatched types
     //~| expected struct `Example`
-    let e: Example2::<u32, 13> = ();
+    let e: Example2<u32, 13> = ();
     //~^ Error: mismatched types
     //~| expected struct `Example2`
-    let e: Example3::<13, u32> = ();
+    let e: Example3<13, u32> = ();
     //~^ Error: mismatched types
     //~| expected struct `Example3`
-    let e: Example3::<7> = ();
+    let e: Example3<7> = ();
     //~^ Error: mismatched types
-    //~| expected struct `Example3<7_usize>`
-    let e: Example4::<7> = ();
+    //~| expected struct `Example3<7>`
+    let e: Example4<7> = ();
     //~^ Error: mismatched types
-    //~| expected struct `Example4<7_usize>`
+    //~| expected struct `Example4<7>`
 }

src/test/ui/const-generics/defaults/mismatch.stderr

@@ -1,56 +1,56 @@
 error[E0308]: mismatched types
-  --> $DIR/mismatch.rs:7:28
+  --> $DIR/mismatch.rs:7:26
    |
-LL |     let e: Example::<13> = ();
-   |            -------------   ^^ expected struct `Example`, found `()`
+LL |     let e: Example<13> = ();
+   |            -----------   ^^ expected struct `Example`, found `()`
    |            |
    |            expected due to this
    |
    = note: expected struct `Example`
            found unit type `()`
 
 error[E0308]: mismatched types
-  --> $DIR/mismatch.rs:10:34
+  --> $DIR/mismatch.rs:10:32
    |
-LL |     let e: Example2::<u32, 13> = ();
-   |            -------------------   ^^ expected struct `Example2`, found `()`
+LL |     let e: Example2<u32, 13> = ();
+   |            -----------------   ^^ expected struct `Example2`, found `()`
    |            |
    |            expected due to this
    |
    = note: expected struct `Example2`
            found unit type `()`
 
 error[E0308]: mismatched types
-  --> $DIR/mismatch.rs:13:34
+  --> $DIR/mismatch.rs:13:32
    |
-LL |     let e: Example3::<13, u32> = ();
-   |            -------------------   ^^ expected struct `Example3`, found `()`
+LL |     let e: Example3<13, u32> = ();
+   |            -----------------   ^^ expected struct `Example3`, found `()`
    |            |
    |            expected due to this
    |
    = note: expected struct `Example3`
            found unit type `()`
 
 error[E0308]: mismatched types
-  --> $DIR/mismatch.rs:16:28
+  --> $DIR/mismatch.rs:16:26
    |
-LL |     let e: Example3::<7> = ();
-   |            -------------   ^^ expected struct `Example3`, found `()`
+LL |     let e: Example3<7> = ();
+   |            -----------   ^^ expected struct `Example3`, found `()`
    |            |
    |            expected due to this
    |
-   = note: expected struct `Example3<7_usize>`
+   = note: expected struct `Example3<7>`
            found unit type `()`
 
 error[E0308]: mismatched types
-  --> $DIR/mismatch.rs:19:28
+  --> $DIR/mismatch.rs:19:26
    |
-LL |     let e: Example4::<7> = ();
-   |            -------------   ^^ expected struct `Example4`, found `()`
+LL |     let e: Example4<7> = ();
+   |            -----------   ^^ expected struct `Example4`, found `()`
    |            |
    |            expected due to this
    |
-   = note: expected struct `Example4<7_usize>`
+   = note: expected struct `Example4<7>`
            found unit type `()`
 
 error: aborting due to 5 previous errors

src/test/ui/const-generics/defaults/rp_impl_trait_fail.rs

@@ -4,16 +4,15 @@ trait Trait {}
 impl<const N: u32> Trait for Uwu<N> {}
 
 fn rawr() -> impl Trait {
-    //~^ error: the trait bound `Uwu<10_u32, 12_u32>: Trait` is not satisfied
+    //~^ error: the trait bound `Uwu<10, 12>: Trait` is not satisfied
     Uwu::<10, 12>
 }
 
-trait Traitor<const N: u8 = 1, const M: u8 = N> { }
+trait Traitor<const N: u8 = 1, const M: u8 = N> {}
 
 impl<const N: u8> Traitor<N, 2> for u32 {}
 impl Traitor<1, 2> for u64 {}
 
-
 fn uwu<const N: u8>() -> impl Traitor<N> {
     //~^ error: the trait bound `u32: Traitor<N>` is not satisfied
     1_u32

src/test/ui/const-generics/defaults/rp_impl_trait_fail.stderr

@@ -1,16 +1,16 @@
-error[E0277]: the trait bound `Uwu<10_u32, 12_u32>: Trait` is not satisfied
+error[E0277]: the trait bound `Uwu<10, 12>: Trait` is not satisfied
   --> $DIR/rp_impl_trait_fail.rs:6:14
    |
 LL | fn rawr() -> impl Trait {
-   |              ^^^^^^^^^^ the trait `Trait` is not implemented for `Uwu<10_u32, 12_u32>`
+   |              ^^^^^^^^^^ the trait `Trait` is not implemented for `Uwu<10, 12>`
 LL |
 LL |     Uwu::<10, 12>
-   |     ------------- return type was inferred to be `Uwu<10_u32, 12_u32>` here
+   |     ------------- return type was inferred to be `Uwu<10, 12>` here
    |
    = help: the trait `Trait` is implemented for `Uwu<N>`
 
 error[E0277]: the trait bound `u32: Traitor<N>` is not satisfied
-  --> $DIR/rp_impl_trait_fail.rs:17:26
+  --> $DIR/rp_impl_trait_fail.rs:16:26
    |
 LL | fn uwu<const N: u8>() -> impl Traitor<N> {
    |                          ^^^^^^^^^^^^^^^ the trait `Traitor<N>` is not implemented for `u32`
@@ -19,11 +19,11 @@ LL |     1_u32
    |     ----- return type was inferred to be `u32` here
    |
    = help: the following other types implement trait `Traitor<N, M>`:
-             <u32 as Traitor<N, 2_u8>>
-             <u64 as Traitor<1_u8, 2_u8>>
+             <u32 as Traitor<N, 2>>
+             <u64 as Traitor<1, 2>>
 
 error[E0277]: the trait bound `u64: Traitor` is not satisfied
-  --> $DIR/rp_impl_trait_fail.rs:22:13
+  --> $DIR/rp_impl_trait_fail.rs:21:13
    |
 LL | fn owo() -> impl Traitor {
    |             ^^^^^^^^^^^^ the trait `Traitor` is not implemented for `u64`
@@ -32,8 +32,8 @@ LL |     1_u64
    |     ----- return type was inferred to be `u64` here
    |
    = help: the following other types implement trait `Traitor<N, M>`:
-             <u32 as Traitor<N, 2_u8>>
-             <u64 as Traitor<1_u8, 2_u8>>
+             <u32 as Traitor<N, 2>>
+             <u64 as Traitor<1, 2>>
 
 error: aborting due to 3 previous errors
 

src/test/ui/const-generics/defaults/trait_objects_fail.rs

@@ -16,7 +16,7 @@ trait Traitor<const N: u8 = 1, const M: u8 = N> {
     }
 }
 
-impl Traitor<2, 3> for bool { }
+impl Traitor<2, 3> for bool {}
 
 fn bar<const N: u8>(arg: &dyn Traitor<N>) -> u8 {
     arg.owo()
@@ -26,5 +26,5 @@ fn main() {
     foo(&10_u32);
     //~^ error: the trait bound `u32: Trait` is not satisfied
     bar(&true);
-    //~^ error: the trait bound `bool: Traitor<{_: u8}>` is not satisfied
+    //~^ error: the trait bound `bool: Traitor<_>` is not satisfied
 }

src/test/ui/const-generics/defaults/trait_objects_fail.stderr

@@ -6,19 +6,19 @@ LL |     foo(&10_u32);
    |     |
    |     required by a bound introduced by this call
    |
-   = help: the trait `Trait<2_u8>` is implemented for `u32`
+   = help: the trait `Trait<2>` is implemented for `u32`
    = note: required for the cast from `u32` to the object type `dyn Trait`
 
-error[E0277]: the trait bound `bool: Traitor<{_: u8}>` is not satisfied
+error[E0277]: the trait bound `bool: Traitor<_>` is not satisfied
   --> $DIR/trait_objects_fail.rs:28:9
    |
 LL |     bar(&true);
-   |     --- ^^^^^ the trait `Traitor<{_: u8}>` is not implemented for `bool`
+   |     --- ^^^^^ the trait `Traitor<_>` is not implemented for `bool`
    |     |
    |     required by a bound introduced by this call
    |
-   = help: the trait `Traitor<2_u8, 3_u8>` is implemented for `bool`
-   = note: required for the cast from `bool` to the object type `dyn Traitor<{_: u8}>`
+   = help: the trait `Traitor<2, 3>` is implemented for `bool`
+   = note: required for the cast from `bool` to the object type `dyn Traitor<_>`
 
 error: aborting due to 2 previous errors