Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 39 insertions, 0 deletions

diff --git a/compiler/rustc_error_codes/src/error_codes/E0040.md b/compiler/rustc_error_codes/src/error_codes/E0040.md
new file mode 100644
index 000000000..1373f8340
--- /dev/null
+++ b/compiler/rustc_error_codes/src/error_codes/E0040.md
@@ -0,0 +1,39 @@
+It is not allowed to manually call destructors in Rust.
+
+Erroneous code example:
+
+```compile_fail,E0040
+struct Foo {
+    x: i32,
+}
+
+impl Drop for Foo {
+    fn drop(&mut self) {
+        println!("kaboom");
+    }
+}
+
+fn main() {
+    let mut x = Foo { x: -7 };
+    x.drop(); // error: explicit use of destructor method
+}
+```
+
+It is unnecessary to do this since `drop` is called automatically whenever a
+value goes out of scope. However, if you really need to drop a value by hand,
+you can use the `std::mem::drop` function:
+
+```
+struct Foo {
+    x: i32,
+}
+impl Drop for Foo {
+    fn drop(&mut self) {
+        println!("kaboom");
+    }
+}
+fn main() {
+    let mut x = Foo { x: -7 };
+    drop(x); // ok!
+}
+```