Added test for mismatched slices, and byte slices.

src/test/ui/const-generics/slice-const-param-mismatch.rs

@@ -0,0 +1,11 @@
+#![feature(const_generics)]
+//~^ WARN the feature `const_generics` is incomplete and may cause the compiler to crash
+
+struct ConstString<const T: &'static str>;
+struct ConstBytes<const T: &'static [u8]>;
+
+pub fn main() {
+    let _: ConstString<"Hello"> = ConstString::<"World">; //~ ERROR mismatched types
+    let _: ConstBytes<b"AAA"> = ConstBytes::<{&[0x41, 0x41, 0x41]}>;
+    let _: ConstBytes<b"AAA"> = ConstBytes::<b"BBB">; //~ ERROR mismatched types
+}

src/test/ui/const-generics/slice-const-param-mismatch.stderr

@@ -0,0 +1,29 @@
+warning: the feature `const_generics` is incomplete and may cause the compiler to crash
+  --> $DIR/slice-const-param-mismatch.rs:1:12
+   |
+LL | #![feature(const_generics)]
+   |            ^^^^^^^^^^^^^^
+   |
+   = note: `#[warn(incomplete_features)]` on by default
+
+error[E0308]: mismatched types
+  --> $DIR/slice-const-param-mismatch.rs:8:35
+   |
+LL |     let _: ConstString<"Hello"> = ConstString::<"World">;
+   |                                   ^^^^^^^^^^^^^^^^^^^^^^ expected `"Hello"`, found `"World"`
+   |
+   = note: expected type `ConstString<>`
+              found type `ConstString<>`
+
+error[E0308]: mismatched types
+  --> $DIR/slice-const-param-mismatch.rs:10:33
+   |
+LL |     let _: ConstBytes<b"AAA"> = ConstBytes::<b"BBB">;
+   |                                 ^^^^^^^^^^^^^^^^^^^^ expected `b"AAA"`, found `b"BBB"`
+   |
+   = note: expected type `ConstBytes<>`
+              found type `ConstBytes<>`
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0308`.

src/test/ui/const-generics/slice-const-param.rs

@@ -7,6 +7,12 @@ pub fn function_with_str<const STRING: &'static str>() -> &'static str {
     STRING
 }
 
+pub fn function_with_bytes<const BYTES: &'static [u8]>() -> &'static [u8] {
+    BYTES
+}
+
 pub fn main() {
     assert_eq!(function_with_str::<"Rust">(), "Rust");
+    assert_eq!(function_with_bytes::<b"AAAA">(), &[0x41, 0x41, 0x41, 0x41]);
+    assert_eq!(function_with_bytes::<{&[0x41, 0x41, 0x41, 0x41]}>(), b"AAAA");
 }

src/test/ui/const-generics/slice-const-param.stderr

@@ -1,5 +1,5 @@
 warning: the feature `const_generics` is incomplete and may cause the compiler to crash
-  --> $DIR/str-const-param.rs:3:12
+  --> $DIR/slice-const-param.rs:3:12
    |
 LL | #![feature(const_generics)]
    |            ^^^^^^^^^^^^^^