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, 20 insertions, 0 deletions

diff --git a/compiler/rustc_error_codes/src/error_codes/E0384.md b/compiler/rustc_error_codes/src/error_codes/E0384.md
new file mode 100644
index 000000000..e21fac079
--- /dev/null
+++ b/compiler/rustc_error_codes/src/error_codes/E0384.md
@@ -0,0 +1,20 @@
+An immutable variable was reassigned.
+
+Erroneous code example:
+
+```compile_fail,E0384
+fn main() {
+    let x = 3;
+    x = 5; // error, reassignment of immutable variable
+}
+```
+
+By default, variables in Rust are immutable. To fix this error, add the keyword
+`mut` after the keyword `let` when declaring the variable. For example:
+
+```
+fn main() {
+    let mut x = 3;
+    x = 5;
+}
+```