blob: 4640363d74999614fe7ba8f94295b8cf35f62f6a (
plain)
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
|
// Copyright Louis Dionne 2013-2017
// Copyright Jason Rice 2017
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
#ifndef TEST_SUPPORT_COUNTER_HPP
#define TEST_SUPPORT_COUNTER_HPP
#include <boost/hana/fwd/at.hpp>
#include <boost/hana/fwd/concept/iterable.hpp>
#include <boost/hana/fwd/drop_front.hpp>
#include <boost/hana/fwd/is_empty.hpp>
#include <boost/hana/integral_constant.hpp>
// Counter - an infinite iterable for the masses
struct Counter_tag { };
template <std::size_t N = 0>
struct Counter {
using hana_tag = Counter_tag;
static constexpr std::size_t value = N;
};
namespace boost { namespace hana {
//////////////////////////////////////////////////////////////////////////
// Iterable
//////////////////////////////////////////////////////////////////////////
template <>
struct at_impl<Counter_tag> {
template <typename T, typename N>
static constexpr decltype(auto) apply(T, N) {
return hana::size_c<T::value + N::value>;
}
};
template <>
struct drop_front_impl<Counter_tag> {
template <typename T, typename N>
static constexpr auto apply(T, N) {
return Counter<T::value + N::value>{};
}
};
template <>
struct is_empty_impl<Counter_tag> {
template <typename Xs>
static constexpr auto apply(Xs)
-> hana::false_
{ return {}; }
};
}} // end namespace boost::hana
#endif // !TEST_SUPPORT_COUNTER_HPP
|
