1 | // |
2 | // immer: immutable data structures for C++ |
3 | // Copyright (C) 2016, 2017, 2018 Juan Pedro Bolivar Puente |
4 | // |
5 | // This software is distributed under the Boost Software License, Version 1.0. |
6 | // See accompanying file LICENSE or copy at http://boost.org/LICENSE_1_0.txt |
7 | // |
8 | |
9 | #pragma once |
10 | |
11 | #include <immer/refcount/no_refcount_policy.hpp> |
12 | |
13 | #include <atomic> |
14 | #include <utility> |
15 | |
16 | namespace immer { |
17 | |
18 | /*! |
19 | * A reference counting policy implemented using a raw `int` count. |
20 | * It is **not thread-safe**. |
21 | */ |
22 | struct unsafe_refcount_policy |
23 | { |
24 | using spinlock_type = no_spinlock; |
25 | |
26 | mutable int refcount; |
27 | |
28 | unsafe_refcount_policy() : refcount{1} {}; |
29 | unsafe_refcount_policy(disowned) : refcount{0} {} |
30 | |
31 | void inc() { ++refcount; } |
32 | bool dec() { return --refcount == 0; } |
33 | void dec_unsafe() { --refcount; } |
34 | bool unique() { return refcount == 1; } |
35 | }; |
36 | |
37 | } // namespace immer |
38 | |