Auto merge of #57542 - Centril:rollup, r=Centril

Rollup of 26 pull requests

Successful merges:

 - #56425 (Redo the docs for Vec::set_len)
 - #56906 (Issue #56905)
 - #57042 (Don't call `FieldPlacement::count` when count is too large)
 - #57175 (Stabilize `let` bindings and destructuring in constants and const fn)
 - #57192 (Change std::error::Error trait documentation to talk about `source` instead of `cause`)
 - #57296 (Fixed the link to the ? operator)
 - #57368 (Use CMAKE_{C,CXX}_COMPILER_LAUNCHER for ccache)
 - #57400 (Rustdoc: update Source Serif Pro and replace Heuristica italic)
 - #57417 (rustdoc: use text-based doctest parsing if a macro is wrapping main)
 - #57433 (Add link destination for `read-ownership`)
 - #57434 (Remove `CrateNum::Invalid`.)
 - #57441 (Supporting backtrace for x86_64-fortanix-unknown-sgx.)
 - #57450 (actually take a slice in this example)
 - #57459 (Reference tracking issue for inherent associated types in diagnostic)
 - #57463 (docs: Fix some 'second-edition' links)
 - #57466 (Remove outdated comment)
 - #57493 (use structured suggestion when casting a reference)
 - #57498 (make note of one more normalization that Paths do)
 - #57499 (note that FromStr does not work for borrowed types)
 - #57505 (Remove submodule step from README)
 - #57510 (Add a profiles section to the manifest)
 - #57511 (Fix undefined behavior)
 - #57519 (Correct RELEASES.md for 1.32.0)
 - #57522 (don't unwrap unexpected tokens in `format!`)
 - #57530 (Fixing a typographical error.)
 - #57535 (Stabilise irrefutable if-let and while-let patterns)

Failed merges:

r? @ghost

4 files changed, 85 insertions, 0 deletions

diff --git a/src/test/ui/pattern/deny-irrefutable-let-patterns.rs b/src/test/ui/pattern/deny-irrefutable-let-patterns.rs
new file mode 100644
index 00000000000..14040c8ada6
--- /dev/null
+++ b/src/test/ui/pattern/deny-irrefutable-let-patterns.rs
@@ -0,0 +1,9 @@
+#![deny(irrefutable_let_patterns)]
+
+fn main() {
+    if let _ = 5 {} //~ ERROR irrefutable if-let pattern
+
+    while let _ = 5 { //~ ERROR irrefutable while-let pattern
+        break;
+    }
+}
diff --git a/src/test/ui/pattern/deny-irrefutable-let-patterns.stderr b/src/test/ui/pattern/deny-irrefutable-let-patterns.stderr
new file mode 100644
index 00000000000..ad8cc2ef897
--- /dev/null
+++ b/src/test/ui/pattern/deny-irrefutable-let-patterns.stderr
@@ -0,0 +1,22 @@
+error: irrefutable if-let pattern
+  --> $DIR/deny-irrefutable-let-patterns.rs:4:5
+   |
+LL |     if let _ = 5 {} //~ ERROR irrefutable if-let pattern
+   |     ^^^^^^^^^^^^^^^
+   |
+note: lint level defined here
+  --> $DIR/deny-irrefutable-let-patterns.rs:1:9
+   |
+LL | #![deny(irrefutable_let_patterns)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: irrefutable while-let pattern
+  --> $DIR/deny-irrefutable-let-patterns.rs:6:5
+   |
+LL | /     while let _ = 5 { //~ ERROR irrefutable while-let pattern
+LL | |         break;
+LL | |     }
+   | |_____^
+
+error: aborting due to 2 previous errors
+
diff --git a/src/test/ui/pattern/enum-variant-generic-args.rs b/src/test/ui/pattern/enum-variant-generic-args.rs
new file mode 100644
index 00000000000..85599530ea6
--- /dev/null
+++ b/src/test/ui/pattern/enum-variant-generic-args.rs
@@ -0,0 +1,43 @@
+// run-pass
+
+#![feature(type_alias_enum_variants)]
+
+#![allow(irrefutable_let_patterns)]
+
+#[allow(dead_code)]
+enum Enum<T> { TSVariant(T), SVariant { v: T } }
+type Alias<T> = Enum<T>;
+type AliasFixed = Enum<()>;
+
+macro_rules! is_variant {
+    (TSVariant, $expr:expr) => (is_variant!(@check TSVariant, (_), $expr));
+    (SVariant, $expr:expr) => (is_variant!(@check SVariant, { v: _ }, $expr));
+    (@check $variant:ident, $matcher:tt, $expr:expr) => (
+        assert!(if let Enum::$variant::<()> $matcher = $expr { true } else { false },
+                "expr does not have correct type");
+    );
+}
+
+fn main() {
+    // Tuple struct variant
+
+    is_variant!(TSVariant, Enum::TSVariant(()));
+    is_variant!(TSVariant, Enum::TSVariant::<()>(()));
+    is_variant!(TSVariant, Enum::<()>::TSVariant(()));
+
+    is_variant!(TSVariant, Alias::TSVariant(()));
+    is_variant!(TSVariant, Alias::<()>::TSVariant(()));
+
+    is_variant!(TSVariant, AliasFixed::TSVariant(()));
+
+    // Struct variant
+
+    is_variant!(SVariant, Enum::SVariant { v: () });
+    is_variant!(SVariant, Enum::SVariant::<()> { v: () });
+    is_variant!(SVariant, Enum::<()>::SVariant { v: () });
+
+    is_variant!(SVariant, Alias::SVariant { v: () });
+    is_variant!(SVariant, Alias::<()>::SVariant { v: () });
+
+    is_variant!(SVariant, AliasFixed::SVariant { v: () });
+}
diff --git a/src/test/ui/pattern/irrefutable-let-patterns.rs b/src/test/ui/pattern/irrefutable-let-patterns.rs
new file mode 100644
index 00000000000..d400ef0bbd6
--- /dev/null
+++ b/src/test/ui/pattern/irrefutable-let-patterns.rs
@@ -0,0 +1,11 @@
+// run-pass
+
+#![allow(irrefutable_let_patterns)]
+
+fn main() {
+    if let _ = 5 {}
+
+    while let _ = 5 {
+        break;
+    }
+}