Add example for Agent.cast/2 (#9142)

1 files changed, 9 insertions, 0 deletions

diff --git a/lib/elixir/lib/agent.ex b/lib/elixir/lib/agent.ex
index 36e80179b..51f9e8c8d 100644
--- a/lib/elixir/lib/agent.ex
+++ b/lib/elixir/lib/agent.ex
@@ -439,6 +439,15 @@ defmodule Agent do
 
   Note that `cast` returns `:ok` immediately, regardless of whether `agent` (or
   the node it should live on) exists.
+
+  ## Examples
+
+      iex> {:ok, pid} = Agent.start_link(fn -> 42 end)
+      iex> Agent.cast(pid, fn state -> state + 1 end)
+      :ok
+      iex> Agent.get(pid, fn state -> state end)
+      43
+
   """
   @spec cast(agent, (state -> state)) :: :ok
   def cast(agent, fun) when is_function(fun, 1) do