content: expand discussion of methods

Fixes golang/go#13818

Change-Id: I22817c0c3bfa3d7e5a769f239a2521c293112a43
Reviewed-on: https://go-review.googlesource.com/18246
Reviewed-by: Rob Pike <r@golang.org>

1 files changed, 30 insertions, 0 deletions

diff --git a/content/methods/indirection-values.go b/content/methods/indirection-values.go
new file mode 100644
index 0000000..04e022b
--- /dev/null
+++ b/content/methods/indirection-values.go
@@ -0,0 +1,30 @@
+// +build OMIT
+
+package main
+
+import (
+	"fmt"
+	"math"
+)
+
+type Vertex struct {
+	X, Y float64
+}
+
+func (v Vertex) Abs() float64 {
+	return math.Sqrt(v.X*v.X + v.Y*v.Y)
+}
+
+func AbsFunc(v Vertex) float64 {
+	return math.Sqrt(v.X*v.X + v.Y*v.Y)
+}
+
+func main() {
+	v := Vertex{3, 4}
+	fmt.Println(v.Abs())
+	fmt.Println(AbsFunc(v))
+
+	p := &Vertex{4, 3}
+	fmt.Println(p.Abs())
+	fmt.Println(AbsFunc(*p))
+}