1 // Copyright 2020 The Pigweed Authors
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License"); you may not
4 // use this file except in compliance with the License. You may obtain a copy of
5 // the License at
6 //
7 // https://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
11 // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
12 // License for the specific language governing permissions and limitations under
13 // the License.
14 #pragma once
15
16 #include <type_traits>
17
18 #include "pw_polyfill/standard_library/namespace.h"
19
20 _PW_POLYFILL_BEGIN_NAMESPACE_STD
21
22 template <class InputIterator, class OutputIterator>
copy(InputIterator first,InputIterator last,OutputIterator dest)23 constexpr OutputIterator copy(InputIterator first,
24 InputIterator last,
25 OutputIterator dest) {
26 while (first != last) {
27 *dest++ = *first++;
28 }
29 return dest;
30 }
31
32 template <typename T>
min(const T & lhs,const T & rhs)33 constexpr const T& min(const T& lhs, const T& rhs) {
34 return (rhs < lhs) ? rhs : lhs;
35 }
36
37 template <typename T>
max(const T & lhs,const T & rhs)38 constexpr const T& max(const T& lhs, const T& rhs) {
39 return (lhs < rhs) ? rhs : lhs;
40 }
41
42 template <class InputIterator, typename T>
find(InputIterator first,InputIterator last,const T & value)43 constexpr InputIterator find(InputIterator first,
44 InputIterator last,
45 const T& value) {
46 for (; first != last; ++first) {
47 if (*first == value) {
48 return first;
49 }
50 }
51 return last;
52 }
53
54 template <typename T>
forward(remove_reference_t<T> & value)55 constexpr T&& forward(remove_reference_t<T>& value) {
56 return static_cast<T&&>(value);
57 }
58
59 template <typename T>
forward(remove_reference_t<T> && value)60 constexpr T&& forward(remove_reference_t<T>&& value) {
61 return static_cast<T&&>(value);
62 }
63
64 template <class LhsIterator, class RhsIterator>
equal(LhsIterator first_l,LhsIterator last_l,RhsIterator first_r,RhsIterator last_r)65 constexpr bool equal(LhsIterator first_l,
66 LhsIterator last_l,
67 RhsIterator first_r,
68 RhsIterator last_r) {
69 while (first_l != last_l && first_r != last_r) {
70 if (*first_l != *first_r) {
71 return false;
72 }
73 ++first_l;
74 ++first_r;
75 }
76 return first_l == last_l && first_r == last_r;
77 }
78
79 template <class LhsIterator, class RhsIterator>
lexicographical_compare(LhsIterator first_l,LhsIterator last_l,RhsIterator first_r,RhsIterator last_r)80 constexpr bool lexicographical_compare(LhsIterator first_l,
81 LhsIterator last_l,
82 RhsIterator first_r,
83 RhsIterator last_r) {
84 while (first_l != last_l && first_r != last_r) {
85 if (*first_l < *first_r) {
86 return true;
87 }
88 if (*first_r < *first_l) {
89 return false;
90 }
91
92 ++first_l;
93 ++first_r;
94 }
95 return (first_l == last_l) && (first_r != last_r);
96 }
97
98 _PW_POLYFILL_END_NAMESPACE_STD
99