1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
|
// Copyright 2019 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef UTIL_STD_UTIL_H_
#define UTIL_STD_UTIL_H_
#include <algorithm>
#include <map>
#include <string>
#include <utility>
#include <vector>
// TODO: This header is included in the openscreen discovery public headers (dns_sd_instance.h),
// which exposes this abseil header. Need to figure out a way to hide it.
#if 0
#include "absl/algorithm/container.h"
#endif
#include "util/stringprintf.h"
namespace openscreen {
template <typename T, size_t N>
constexpr size_t countof(T (&array)[N]) {
return N;
}
// std::basic_string::data() has no mutable overload prior to C++17 [1].
// Hence this overload is provided.
// Note: str[0] is safe even for empty strings, as they are guaranteed to be
// null-terminated [2].
//
// [1] http://en.cppreference.com/w/cpp/string/basic_string/data
// [2] http://en.cppreference.com/w/cpp/string/basic_string/operator_at
template <typename CharT, typename Traits, typename Allocator>
CharT* data(std::basic_string<CharT, Traits, Allocator>& str) {
return std::addressof(str[0]);
}
std::string Join(const std::vector<std::string>& strings,
const char* delimiter);
template <typename Key, typename Value>
void RemoveValueFromMap(std::map<Key, Value*>* map, Value* value) {
for (auto it = map->begin(); it != map->end();) {
if (it->second == value) {
it = map->erase(it);
} else {
++it;
}
}
}
#if 0
template <typename ForwardIteratingContainer>
bool AreElementsSortedAndUnique(const ForwardIteratingContainer& c) {
return absl::c_is_sorted(c) && (absl::c_adjacent_find(c) == c.end());
}
#endif
template <typename RandomAccessContainer>
void SortAndDedupeElements(RandomAccessContainer* c) {
std::sort(c->begin(), c->end());
const auto new_end = std::unique(c->begin(), c->end());
c->erase(new_end, c->end());
}
// Append the provided elements together into a single vector. This can be
// useful when creating a vector of variadic templates in the ctor.
//
// This is the base case for the recursion
template <typename T>
std::vector<T>&& Append(std::vector<T>&& so_far) {
return std::move(so_far);
}
// This is the recursive call. Depending on the number of remaining elements, it
// either calls into itself or into the above base case.
template <typename T, typename TFirst, typename... TOthers>
std::vector<T>&& Append(std::vector<T>&& so_far,
TFirst&& new_element,
TOthers&&... new_elements) {
so_far.push_back(std::move(new_element));
return Append(std::move(so_far), std::move(new_elements)...);
}
// Creates an empty vector with |size| elements reserved. Intended to be used as
// GetEmptyVectorOfSize<T>(sizeof...(variadic_input))
template <typename T>
std::vector<T> GetVectorWithCapacity(size_t size) {
std::vector<T> results;
results.reserve(size);
return results;
}
} // namespace openscreen
#endif // UTIL_STD_UTIL_H_
|
