Add exp_maps.go

Author: devlights

examples/generics/examples.go

@@ -2,6 +2,7 @@ package generics
 
 import (
 	"github.com/devlights/try-golang/examples/generics/exp_constraints"
+	"github.com/devlights/try-golang/examples/generics/exp_maps"
 	"github.com/devlights/try-golang/examples/generics/exp_slices"
 	"github.com/devlights/try-golang/examples/generics/typeconstraints"
 	"github.com/devlights/try-golang/examples/generics/typeparameters"
@@ -24,4 +25,5 @@ func (r *register) Regist(m mapping.ExampleMapping) {
 	typeconstraints.NewRegister().Regist(m)
 	exp_constraints.NewRegister().Regist(m)
 	exp_slices.NewRegister().Regist(m)
+	exp_maps.NewRegister().Regist(m)
 }

examples/generics/exp_maps/examples.go

@@ -0,0 +1,20 @@
+package exp_maps
+
+import (
+	"github.com/devlights/try-golang/mapping"
+)
+
+type (
+	register struct{}
+)
+
+// NewRegister は、generics パッケージ用の lib.Register を返します.
+func NewRegister() mapping.Register {
+	r := new(register)
+	return r
+}
+
+// Regist は、generics パッケージ配下に存在するサンプルを登録します.
+func (r *register) Regist(m mapping.ExampleMapping) {
+	m["generics_exp_maps"] = ExpMaps
+}

examples/generics/exp_maps/exp_maps.go

@@ -0,0 +1,27 @@
+package exp_maps
+
+import (
+	"github.com/devlights/gomy/output"
+	"golang.org/x/exp/maps"
+)
+
+// ExpMaps -- Go 1.18 リリース時には含まれなかったジェネリクス対応 汎用map処理が定義されている golang.org/x/exp/maps パッケージのサンプルです。
+func ExpMaps() error {
+	var (
+		m1 = map[string]int{"hello": 100, "world": 101}
+		m2 = map[string]int{"world": 101, "hello": 100}
+		k  []string
+		v  []int
+	)
+
+	k = maps.Keys(m1)
+	v = maps.Values(m1)
+
+	output.Stdoutl("[maps.Keys]", k, v)
+	output.Stdoutl("[maps.Values]", maps.Equal(m1, m2))
+
+	maps.Clear(m1)
+	output.Stdoutl("[maps.Clear]", m1, m2)
+
+	return nil
+}