1// Copyright (c) 2017-2023 Uber Technologies, Inc.
 2//
 3// Permission is hereby granted, free of charge, to any person obtaining a copy
 4// of this software and associated documentation files (the "Software"), to deal
 5// in the Software without restriction, including without limitation the rights
 6// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 7// copies of the Software, and to permit persons to whom the Software is
 8// furnished to do so, subject to the following conditions:
 9//
10// The above copyright notice and this permission notice shall be included in
11// all copies or substantial portions of the Software.
12//
13// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
14// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
15// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
16// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
17// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
18// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
19// THE SOFTWARE.
20
21//go:build go1.20
22// +build go1.20
23
24package multierr
25
26// Unwrap returns a list of errors wrapped by this multierr.
27func (merr *multiError) Unwrap() []error {
28	return merr.Errors()
29}
30
31type multipleErrors interface {
32	Unwrap() []error
33}
34
35func extractErrors(err error) []error {
36	if err == nil {
37		return nil
38	}
39
40	// check if the given err is an Unwrapable error that
41	// implements multipleErrors interface.
42	eg, ok := err.(multipleErrors)
43	if !ok {
44		return []error{err}
45	}
46
47	return append(([]error)(nil), eg.Unwrap()...)
48}