From afe79d8b17a3cc120a96201a43487c16279a0aef Mon Sep 17 00:00:00 2001
From: Marc-Andre Lafortune <github@marc-andre.ca>
Date: Sun, 18 Oct 2020 15:20:03 -0400
Subject: [PATCH] Fix signature for `Enumerable#find`.

---
 stdlib/builtin/enumerable.rbs | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/stdlib/builtin/enumerable.rbs b/stdlib/builtin/enumerable.rbs
index a410db355..67ecd5e82 100644
--- a/stdlib/builtin/enumerable.rbs
+++ b/stdlib/builtin/enumerable.rbs
@@ -307,11 +307,17 @@ module Enumerable[unchecked out Elem, out Return]: _Each[Elem, Return]
   # ```
   def to_h: () -> ::Hash[untyped, untyped]
 
-  def each_slice: (Integer n) { (::Array[Elem] arg0) -> untyped } -> NilClass
+  def each_slice: (Integer n) { (::Array[Elem]) -> untyped } -> NilClass
                 | (Integer n) -> ::Enumerator[::Array[Elem], Return]
 
-  def find: (?Proc ifnone) { (Elem arg0) -> bool } -> Elem?
-          | (?Proc ifnone) -> ::Enumerator[Elem, Return]
+  interface _NotFound[T]
+    def call: () -> T
+  end
+
+  def find: () { (Elem) -> bool } -> Elem?
+          | () -> ::Enumerator[Elem, Elem?]
+          | [T] (_NotFound[T] ifnone) { (Elem) -> bool } -> (Elem | T)
+          | [T] (_NotFound[T] ifnone) -> ::Enumerator[Elem, Elem | T]
 
   def flat_map: [U] () { (Elem arg0) -> U } -> U
               | () -> ::Enumerator[Elem, Return]