Add ToStringMapStruct()

README.md

@@ -432,6 +432,7 @@ The following functions and methods exist:
  * `GetInt(key string) : int`
  * `GetString(key string) : string`
  * `GetStringMap(key string) : map[string]interface{}`
+ * `GetStringMapStruct(key string) : map[string]struct{}`
  * `GetStringMapString(key string) : map[string]string`
  * `GetStringSlice(key string) : []string`
  * `GetTime(key string) : time.Time`

viper.go

@@ -712,6 +712,12 @@ func (v *Viper) GetStringSlice(key string) []string {
 	return cast.ToStringSlice(v.Get(key))
 }
 
+// GetStringMapStruct returns the value associated with the key as a slice of strings.
+func GetStringMapStruct(key string) map[string]struct{} { return v.GetStringMapStruct(key) }
+func (v *Viper) GetStringMapStruct(key string) map[string]struct{} {
+	return cast.ToStringMapStruct(v.Get(key))
+}
+
 // GetStringMap returns the value associated with the key as a map of interfaces.
 func GetStringMap(key string) map[string]interface{} { return v.GetStringMap(key) }
 func (v *Viper) GetStringMap(key string) map[string]interface{} {

viper_test.go

@@ -1076,6 +1076,10 @@ func TestMergeConfig(t *testing.T) {
 		t.Fatalf("len(world) != 4, = %d", len(world))
 	}
 
+	if world := v.GetStringMapStruct("hello.world"); len(world) != 4 {
+		t.Fatalf("len(world) != 4, = %d, %#v", len(world), world)
+	}
+
 	if fu := v.GetString("fu"); fu != "" {
 		t.Fatalf("fu != \"\", = %s", fu)
 	}