feat(Type): add driver.Valuer implementation to Optional type

type/interfaces.go

@@ -2,6 +2,7 @@ package Type
 
 import (
 	"database/sql"
+	"database/sql/driver"
 	"encoding/json"
 )
 
@@ -50,6 +51,8 @@ var (
 	_ ValueContainer  = (*Result[any])(nil)
 	_ sql.Scanner     = (*Optional[any])(nil)
 	_ sql.Scanner     = (*Result[any])(nil)
+	_ driver.Valuer   = (*Optional[any])(nil)
+	// _ driver.Valuer   = (*Result[any])(nil)
 	_ json.Marshaler = (*Optional[any])(nil)
 	// _ json.Marshaler   = (*Result[any])(nil)
 	_ json.Unmarshaler = (*Optional[any])(nil)

type/optional.go

@@ -2,7 +2,9 @@ package Type
 
 import (
 	"database/sql"
+	"database/sql/driver"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"reflect"
 	"time"
@@ -285,3 +287,34 @@ func (opt *Optional[T]) UnmarshalJSON(data []byte) error {
 	opt.present = true
 	return nil
 }
+
+func (o Optional[T]) Value() (driver.Value, error) {
+	if !o.present {
+		return nil, nil
+	}
+
+	switch v := any(o.Value).(type) {
+
+	case string, bool,
+		int, int8, int16, int32, int64,
+		uint, uint8, uint16, uint32, uint64, uintptr,
+		float32, float64,
+		complex64, complex128:
+		return v, nil
+
+	case *string, *bool,
+		*int, *int8, *int16, *int32, *int64,
+		*uint, *uint8, *uint16, *uint32, *uint64, *uintptr,
+		*float32, *float64,
+		*complex64, *complex128:
+		return v, nil
+
+	case fmt.Stringer:
+		return v.String(), nil
+	case driver.Valuer:
+		return v.Value()
+
+	default:
+		return nil, errors.New("unsupported type for Optional")
+	}
+}