From c12ae447fced31c806ae788d7d53d6c24f5a05ff Mon Sep 17 00:00:00 2001
From: George Xie <george@xiegeo.com>
Date: Sun, 11 Dec 2022 02:16:37 +0800
Subject: [PATCH] doc: show ExampleB3 in readme (#9)

---
 README.md | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/README.md b/README.md
index 14098d2..9cf75a6 100644
--- a/README.md
+++ b/README.md
@@ -56,6 +56,22 @@ Functions like `True(bool)` and friends. To assert a condition or panic.
 `B1`, `B2`... are generic assertions that pass their first inputs unmodified with compile time type info preserved.
 They return a function to specify what assertions are made on each field.
 
+``` go
+func ExampleB3() {
+    // lets say we have an io.RuneReader
+    readRune := func() (r rune, size int, err error) {
+        return 'a', 1, nil
+    }
+
+    // that must return 1 byte runes and never err out
+    char, _, _ := must.B3(readRune())(must.Any, 1, nil)
+    fmt.Println(string(char))
+
+    // output:
+    // a
+}
+```
+
 Assertions have optional debug arguments, to provide additional information when
 violated. Usually, just pass in the line comment as string.