1 /*  Copyright (C) 2012-2021 by László Nagy
2     This file is part of Bear.
3 
4     Bear is a tool to generate compilation database for clang tooling.
5 
6     Bear is free software: you can redistribute it and/or modify
7     it under the terms of the GNU General Public License as published by
8     the Free Software Foundation, either version 3 of the License, or
9     (at your option) any later version.
10 
11     Bear is distributed in the hope that it will be useful,
12     but WITHOUT ANY WARRANTY; without even the implied warranty of
13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14     GNU General Public License for more details.
15 
16     You should have received a copy of the GNU General Public License
17     along with this program.  If not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #pragma once
21 
22 #include <map>
23 #include <string>
24 
25 namespace sys::env {
26 
27     // Memory resource guard class.
28     //
29     // The OS expect `const char**`, but the caller usually manipulated
30     // the values in different form. This class let the caller use a more
31     // convenient form (`std::map<std::string, std::string>`)  to use,
32     // but makes the final `const char**` not leak.
33     class Guard {
34     public:
35         explicit Guard(const std::map<std::string, std::string>& environ);
36 
37         [[nodiscard]] const char** data() const;
38 
39     public:
40         Guard() = delete;
41         ~Guard() noexcept;
42 
43         Guard(Guard&&) noexcept = delete;
44         Guard(Guard const&) = delete;
45 
46         Guard& operator=(Guard&&) noexcept = delete;
47         Guard& operator=(Guard const&) = delete;
48 
49     private:
50         const char** data_;
51     };
52 }
53