From 43950edc4f26a07055fb917fa8bbb262276e2a08 Mon Sep 17 00:00:00 2001
From: Martin Fischer <martin@push-f.com>
Date: Fri, 26 Nov 2021 09:54:23 +0100
Subject: doc: suggest splitting traits in two

---
 README.md | 22 +++++++++++++++++-----
 1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/README.md b/README.md
index 6a80661..3fb8d39 100644
--- a/README.md
+++ b/README.md
@@ -114,25 +114,37 @@ fn example(&self) -> Result<Vec<Self::Item>, Self::Error>;
 ## How does dynamize deal with method generics?
 
 In order to be object-safe methods must not have generics, so dynamize simply
-moves them to the trait definition:
+moves them to the trait definition. For the following source code:
 
 ```rust
+#[dynamize::dynamize]
 trait Gen {
-    fn foobar<A>(&self, a: A) -> A;
+    type Result: std::fmt::Display;
+
+    fn foo<A>(&self, a: A) -> Self::Result;
+    fn bar<A, B>(&self, a: A, b: B) -> Self::Result;
+    fn buz(&self) -> Self::Result;
 }
 ```
 
-becomes
+dynamize generates the following trait:
 
 ```rust
-trait DynGen<A> {
-    fn foobar(&self, a: A) -> A;
+trait DynGen<A, B> {
+    fn foo(&self, a: A) -> Box<dyn std::fmt::Display + '_>;
+    fn bar(&self, a: A, b: B) -> Box<dyn std::fmt::Display + '_>;
+    fn buz(&self) -> Box<dyn std::fmt::Display + '_>;
 }
 ```
 
 If two method type parameters have the same name, dynamize enforces that they
 also have the same bounds and only adds the parameter once to the trait.
 
+Note that in the dynamized trait calling the `buz` method now requires you to
+specify both generic types, even though they aren't actually required by the
+method. You can avoid this by splitting the original trait in two, i.e. moving
+the `buz` method to a separate trait, which can be dynamized separately.
+
 ## Dynamize supports async
 
 Dynamize supports async out of the box. Since Rust however does not yet support
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