net: add examples for IPv4, ParseCIDR & IPv4Mask

Further examples to support the net package.

See issue #5757

Change-Id: I839fd97a468c8d9195e8f4a0ee886ba50ca3f382
Reviewed-on: https://go-review.googlesource.com/42912
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

diff --git a/src/net/example_test.go b/src/net/example_test.go
index 9dd173245459bb1eef09910838cdaec6a001c263..bfab21c589f0bcfe54d0fce40c10b20c75b630e5 100644 (file)
--- a/src/net/example_test.go
+++ b/src/net/example_test.go
@@ -36,6 +36,35 @@ func ExampleListener() {
        }
 }
 
+func ExampleIPv4() {
+       fmt.Println(net.IPv4(8, 8, 8, 8))
+
+       // Output:
+       // 8.8.8.8
+}
+
+func ExampleParseCIDR() {
+       ipv4Addr, ipv4Net, err := net.ParseCIDR("192.0.2.1/16")
+       if err != nil {
+               log.Fatal(err)
+       }
+       fmt.Println(ipv4Addr)
+       fmt.Println(ipv4Net)
+
+       ipv6Addr, ipv6Net, err := net.ParseCIDR("2001:db8:a0b:12f0::1/32")
+       if err != nil {
+               log.Fatal(err)
+       }
+       fmt.Println(ipv6Addr)
+       fmt.Println(ipv6Net)
+
+       // Output:
+       // 192.0.2.1
+       // 192.0.0.0/16
+       // 2001:db8:a0b:12f0::1
+       // 2001:db8::/32
+}
+
 func ExampleCIDRMask() {
        // This mask corresponds to a /31 subnet for IPv4.
        fmt.Println(net.CIDRMask(31, 32))
@@ -47,3 +76,10 @@ func ExampleCIDRMask() {
        // fffffffe
        // ffffffffffffffff0000000000000000
 }
+
+func ExampleIPv4Mask() {
+       fmt.Println(net.IPv4Mask(255, 255, 255, 0))
+
+       // Output:
+       // ffffff00
+}