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
|
#pragma once
#include <tuple>
#include <utility>
namespace phosphor
{
namespace dbus
{
namespace monitoring
{
/** @brief A tuple of references. */
template <typename... T>
using TupleOfRefs = std::tuple<std::reference_wrapper<T>...>;
namespace detail
{
/** @brief Less than implementation for tuples of references. */
template <size_t size, size_t i, typename T, typename U>
struct TupleOfRefsLess
{
static constexpr bool compare(const T& l, const U& r)
{
if (std::get<i>(l).get() < std::get<i>(r).get())
{
return true;
}
if (std::get<i>(r).get() < std::get<i>(l).get())
{
return false;
}
return TupleOfRefsLess<size, i + 1, T, U>::compare(l, r);
}
};
/** @brief Less than specialization for tuple element sizeof...(tuple) +1. */
template <size_t size, typename T, typename U>
struct TupleOfRefsLess<size, size, T, U>
{
static constexpr bool compare(const T& l, const U& r)
{
return false;
}
};
} // namespace detail
/** @brief Less than comparison for tuples of references. */
struct TupleOfRefsLess
{
template <typename... T, typename... U>
constexpr bool operator()(const TupleOfRefs<T...>& l,
const TupleOfRefs<U...>& r) const
{
static_assert(sizeof...(T) == sizeof...(U),
"Cannot compare tuples of different lengths.");
return detail::TupleOfRefsLess<sizeof...(T), 0, TupleOfRefs<T...>,
TupleOfRefs<U...>>::compare(l, r);
}
};
} // namespace monitoring
} // namespace dbus
} // namespace phosphor
|