1//     __ _____ _____ _____
2//  __|  |   __|     |   | |  JSON for Modern C++
3// |  |  |__   |  |  | | | |  version 3.11.2
4// |_____|_____|_____|_|___|  https://github.com/nlohmann/json
5//
6// SPDX-FileCopyrightText: 2013-2022 Niels Lohmann <https://nlohmann.me>
7// SPDX-License-Identifier: MIT
8
9#pragma once
10
11#include <cstring> // strlen
12#include <string> // string
13#include <utility> // forward
14
15#include <nlohmann/detail/meta/cpp_future.hpp>
16#include <nlohmann/detail/meta/detected.hpp>
17
18NLOHMANN_JSON_NAMESPACE_BEGIN
19namespace detail
20{
21
22inline std::size_t concat_length()
23{
24    return 0;
25}
26
27template<typename... Args>
28inline std::size_t concat_length(const char* cstr, Args&& ... rest);
29
30template<typename StringType, typename... Args>
31inline std::size_t concat_length(const StringType& str, Args&& ... rest);
32
33template<typename... Args>
34inline std::size_t concat_length(const char /*c*/, Args&& ... rest)
35{
36    return 1 + concat_length(std::forward<Args>(rest)...);
37}
38
39template<typename... Args>
40inline std::size_t concat_length(const char* cstr, Args&& ... rest)
41{
42    // cppcheck-suppress ignoredReturnValue
43    return ::strlen(cstr) + concat_length(std::forward<Args>(rest)...);
44}
45
46template<typename StringType, typename... Args>
47inline std::size_t concat_length(const StringType& str, Args&& ... rest)
48{
49    return str.size() + concat_length(std::forward<Args>(rest)...);
50}
51
52template<typename OutStringType>
53inline void concat_into(OutStringType& /*out*/)
54{}
55
56template<typename StringType, typename Arg>
57using string_can_append = decltype(std::declval<StringType&>().append(std::declval < Arg && > ()));
58
59template<typename StringType, typename Arg>
60using detect_string_can_append = is_detected<string_can_append, StringType, Arg>;
61
62template<typename StringType, typename Arg>
63using string_can_append_op = decltype(std::declval<StringType&>() += std::declval < Arg && > ());
64
65template<typename StringType, typename Arg>
66using detect_string_can_append_op = is_detected<string_can_append_op, StringType, Arg>;
67
68template<typename StringType, typename Arg>
69using string_can_append_iter = decltype(std::declval<StringType&>().append(std::declval<const Arg&>().begin(), std::declval<const Arg&>().end()));
70
71template<typename StringType, typename Arg>
72using detect_string_can_append_iter = is_detected<string_can_append_iter, StringType, Arg>;
73
74template<typename StringType, typename Arg>
75using string_can_append_data = decltype(std::declval<StringType&>().append(std::declval<const Arg&>().data(), std::declval<const Arg&>().size()));
76
77template<typename StringType, typename Arg>
78using detect_string_can_append_data = is_detected<string_can_append_data, StringType, Arg>;
79
80template < typename OutStringType, typename Arg, typename... Args,
81           enable_if_t < !detect_string_can_append<OutStringType, Arg>::value
82                         && detect_string_can_append_op<OutStringType, Arg>::value, int > = 0 >
83inline void concat_into(OutStringType& out, Arg && arg, Args && ... rest);
84
85template < typename OutStringType, typename Arg, typename... Args,
86           enable_if_t < !detect_string_can_append<OutStringType, Arg>::value
87                         && !detect_string_can_append_op<OutStringType, Arg>::value
88                         && detect_string_can_append_iter<OutStringType, Arg>::value, int > = 0 >
89inline void concat_into(OutStringType& out, const Arg& arg, Args && ... rest);
90
91template < typename OutStringType, typename Arg, typename... Args,
92           enable_if_t < !detect_string_can_append<OutStringType, Arg>::value
93                         && !detect_string_can_append_op<OutStringType, Arg>::value
94                         && !detect_string_can_append_iter<OutStringType, Arg>::value
95                         && detect_string_can_append_data<OutStringType, Arg>::value, int > = 0 >
96inline void concat_into(OutStringType& out, const Arg& arg, Args && ... rest);
97
98template<typename OutStringType, typename Arg, typename... Args,
99         enable_if_t<detect_string_can_append<OutStringType, Arg>::value, int> = 0>
100inline void concat_into(OutStringType& out, Arg && arg, Args && ... rest)
101{
102    out.append(std::forward<Arg>(arg));
103    concat_into(out, std::forward<Args>(rest)...);
104}
105
106template < typename OutStringType, typename Arg, typename... Args,
107           enable_if_t < !detect_string_can_append<OutStringType, Arg>::value
108                         && detect_string_can_append_op<OutStringType, Arg>::value, int > >
109inline void concat_into(OutStringType& out, Arg&& arg, Args&& ... rest)
110{
111    out += std::forward<Arg>(arg);
112    concat_into(out, std::forward<Args>(rest)...);
113}
114
115template < typename OutStringType, typename Arg, typename... Args,
116           enable_if_t < !detect_string_can_append<OutStringType, Arg>::value
117                         && !detect_string_can_append_op<OutStringType, Arg>::value
118                         && detect_string_can_append_iter<OutStringType, Arg>::value, int > >
119inline void concat_into(OutStringType& out, const Arg& arg, Args&& ... rest)
120{
121    out.append(arg.begin(), arg.end());
122    concat_into(out, std::forward<Args>(rest)...);
123}
124
125template < typename OutStringType, typename Arg, typename... Args,
126           enable_if_t < !detect_string_can_append<OutStringType, Arg>::value
127                         && !detect_string_can_append_op<OutStringType, Arg>::value
128                         && !detect_string_can_append_iter<OutStringType, Arg>::value
129                         && detect_string_can_append_data<OutStringType, Arg>::value, int > >
130inline void concat_into(OutStringType& out, const Arg& arg, Args&& ... rest)
131{
132    out.append(arg.data(), arg.size());
133    concat_into(out, std::forward<Args>(rest)...);
134}
135
136template<typename OutStringType = std::string, typename... Args>
137inline OutStringType concat(Args && ... args)
138{
139    OutStringType str;
140    str.reserve(concat_length(std::forward<Args>(args)...));
141    concat_into(str, std::forward<Args>(args)...);
142    return str;
143}
144
145}  // namespace detail
146NLOHMANN_JSON_NAMESPACE_END
147