1 files changed, 35 insertions, 0 deletions
diff --git a/src/tools/clippy/src/docs/derivable_impls.txt b/src/tools/clippy/src/docs/derivable_impls.txt
new file mode 100644
index 000000000..5cee43956
--- /dev/null
+++ b/src/tools/clippy/src/docs/derivable_impls.txt
@@ -0,0 +1,35 @@
+### What it does
+Detects manual `std::default::Default` implementations that are identical to a derived implementation.
+
+### Why is this bad?
+It is less concise.
+
+### Example
+```
+struct Foo {
+    bar: bool
+}
+
+impl Default for Foo {
+    fn default() -> Self {
+        Self {
+            bar: false
+        }
+    }
+}
+```
+
+Use instead:
+```
+#[derive(Default)]
+struct Foo {
+    bar: bool
+}
+```
+
+### Known problems
+Derive macros [sometimes use incorrect bounds](https://github.com/rust-lang/rust/issues/26925)
+in generic types and the user defined `impl` may be more generalized or
+specialized than what derive will produce. This lint can't detect the manual `impl`
+has exactly equal bounds, and therefore this lint is disabled for types with
+generic parameters.
+\ No newline at end of file