bytes: add example with (*Buffer).Cap, (*Buffer).Read, (*Buffer).ReadByte

Change-Id: Ieb107fdfccde9f054491f667a384b16f7af71dea
Reviewed-on: https://go-review.googlesource.com/c/go/+/355289
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Trust: Cherry Mui <cherryyz@google.com>

diff --git a/src/bytes/example_test.go b/src/bytes/example_test.go
index d04b088fabbc4b683dd372d0acac9f3bacdf796d..54a7aa6ae6c04960ce88f6b0d9cabbc01b46acbe 100644 (file)
--- a/src/bytes/example_test.go
+++ b/src/bytes/example_test.go
@@ -37,6 +37,16 @@ func ExampleBuffer_Bytes() {
        // Output: hello world
 }
 
+func ExampleBuffer_Cap() {
+       buf1 := bytes.NewBuffer(make([]byte, 10))
+       buf2 := bytes.NewBuffer(make([]byte, 0, 10))
+       fmt.Println(buf1.Cap())
+       fmt.Println(buf2.Cap())
+       // Output:
+       // 10
+       // 10
+}
+
 func ExampleBuffer_Grow() {
        var b bytes.Buffer
        b.Grow(64)
@@ -67,6 +77,39 @@ func ExampleBuffer_Next() {
        // e
 }
 
+func ExampleBuffer_Read() {
+       var b bytes.Buffer
+       b.Grow(64)
+       b.Write([]byte("abcde"))
+       rdbuf := make([]byte, 1)
+       n, err := b.Read(rdbuf)
+       if err != nil {
+               panic(err)
+       }
+       fmt.Println(n)
+       fmt.Println(b.String())
+       fmt.Println(string(rdbuf))
+       // Output
+       // 1
+       // bcde
+       // a
+}
+
+func ExampleBuffer_ReadByte() {
+       var b bytes.Buffer
+       b.Grow(64)
+       b.Write([]byte("abcde"))
+       c, err := b.ReadByte()
+       if err != nil {
+               panic(err)
+       }
+       fmt.Println(c)
+       fmt.Println(b.String())
+       // Output
+       // 97
+       // bcde
+}
+
 func ExampleCompare() {
        // Interpret Compare's result by comparing it to zero.
        var a, b []byte