Bitcoin Core  0.19.99
P2P Digital Currency
vector.h
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1 // Copyright (c) 2019 The Bitcoin Core developers
2 // Distributed under the MIT software license, see the accompanying
3 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
4 
5 #ifndef BITCOIN_UTIL_VECTOR_H
6 #define BITCOIN_UTIL_VECTOR_H
7 
8 #include <initializer_list>
9 #include <type_traits>
10 #include <vector>
11 
19 template<typename... Args>
20 inline std::vector<typename std::common_type<Args...>::type> Vector(Args&&... args)
21 {
22  std::vector<typename std::common_type<Args...>::type> ret;
23  ret.reserve(sizeof...(args));
24  // The line below uses the trick from https://www.experts-exchange.com/articles/32502/None-recursive-variadic-templates-with-std-initializer-list.html
25  (void)std::initializer_list<int>{(ret.emplace_back(std::forward<Args>(args)), 0)...};
26  return ret;
27 }
28 
30 template<typename V>
31 inline V Cat(V v1, V&& v2)
32 {
33  v1.reserve(v1.size() + v2.size());
34  for (auto& arg : v2) {
35  v1.push_back(std::move(arg));
36  }
37  return v1;
38 }
39 
41 template<typename V>
42 inline V Cat(V v1, const V& v2)
43 {
44  v1.reserve(v1.size() + v2.size());
45  for (const auto& arg : v2) {
46  v1.push_back(arg);
47  }
48  return v1;
49 }
50 
51 #endif // BITCOIN_UTIL_VECTOR_H
std::vector< typename std::common_type< Args... >::type > Vector(Args &&... args)
Construct a vector with the specified elements.
Definition: vector.h:20
V Cat(V v1, V &&v2)
Concatenate two vectors, moving elements.
Definition: vector.h:31