From e8acc2f9cd372ee00a56fd83395c816ac00931d7 Mon Sep 17 00:00:00 2001
From: moznion <moznion@mail.moznion.net>
Date: Fri, 10 Jun 2022 22:17:30 -0700
Subject: [PATCH] Support Option[T]#Unwrap() method

Signed-off-by: moznion <moznion@mail.moznion.net>
---
 examples_test.go | 10 ++++++++++
 option.go        |  7 +++++++
 option_test.go   |  6 ++++++
 3 files changed, 23 insertions(+)

diff --git a/examples_test.go b/examples_test.go
index 0ff0bb3..476b24b 100644
--- a/examples_test.go
+++ b/examples_test.go
@@ -25,6 +25,16 @@ func ExampleOption_IsSome() {
 	// false
 }
 
+func ExampleOption_Unwrap() {
+	fmt.Printf("%v\n", Some[int](12345).Unwrap())
+	fmt.Printf("%v\n", None[int]().Unwrap())
+	fmt.Printf("%v\n", None[*int]().Unwrap())
+	// Output:
+	// 12345
+	// 0
+	// <nil>
+}
+
 func ExampleOption_Take() {
 	some := Some[int](1)
 	v, err := some.Take()
diff --git a/option.go b/option.go
index 7c1c676..97a885d 100644
--- a/option.go
+++ b/option.go
@@ -36,6 +36,13 @@ func (o Option[T]) IsSome() bool {
 	return o.exists != nil
 }
 
+// Unwrap returns the value regardless of Some/None status.
+// If the Option value is Some, this method returns the actual value.
+// On the other hand, if the Option value is None, this method returns the *default* value according to the type.
+func (o Option[T]) Unwrap() T {
+	return o.value
+}
+
 // Take takes the contained value in Option.
 // If Option value is Some, this returns the value that is contained in Option.
 // On the other hand, this returns an ErrNoneValueTaken as the second return value.
diff --git a/option_test.go b/option_test.go
index cdbe50d..0de9ebf 100644
--- a/option_test.go
+++ b/option_test.go
@@ -18,6 +18,12 @@ func TestOption_IsSome(t *testing.T) {
 	assert.True(t, Some[int](123).IsSome())
 }
 
+func TestOption_Unwrap(t *testing.T) {
+	assert.Equal(t, "foo", Some[string]("foo").Unwrap())
+	assert.Equal(t, "", None[string]().Unwrap())
+	assert.Nil(t, None[*string]().Unwrap())
+}
+
 func TestOption_Take(t *testing.T) {
 	v, err := Some[int](123).Take()
 	assert.NoError(t, err)