Rollup merge of #69670 - GuillaumeGomez:explain-e0379, r=Dylan-DPC

Add explanation for E0379 r? @Dylan-DPC
rust-lang · Mar 3, 2020 · f8c026b · f8c026b
2 parents 587ca17 + c92267a
commit f8c026b
Showing 1 changed file with 12 additions and 0 deletions.
diff --git a/src/librustc_error_codes/error_codes/E0379.md b/src/librustc_error_codes/error_codes/E0379.md
@@ -1,3 +1,15 @@
+A trait method was declared const.
+
+Erroneous code example:
+
+```compile_fail,E0379
+#![feature(const_fn)]
+
+trait Foo {
+    const fn bar() -> u32; // error!
+}
+```
+
 Trait methods cannot be declared `const` by design. For more information, see
 [RFC 911].