1 // Copyright Louis Dionne 2013-2017
2 // Distributed under the Boost Software License, Version 1.0.
3 // (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
5 #include <boost/hana/any_of.hpp>
6 #include <boost/hana/assert.hpp>
7 #include <boost/hana/bool.hpp>
8 #include <boost/hana/equal.hpp>
9 #include <boost/hana/find_if.hpp>
10 #include <boost/hana/fwd/at.hpp>
11 #include <boost/hana/fwd/drop_front.hpp>
12 #include <boost/hana/fwd/is_empty.hpp>
13 #include <boost/hana/integral_constant.hpp>
14 #include <boost/hana/optional.hpp>
15 namespace hana = boost::hana;
18 // A simple infinite Iterable.
22 namespace boost { namespace hana {
24 struct at_impl<counter<i>> {
26 static constexpr auto apply(counter<i>, N const&) {
27 return hana::int_c<i + N::value>;
32 struct drop_front_impl<counter<i>> {
34 static constexpr auto apply(counter<i>, N) { return counter<i + N::value>{}; }
38 struct is_empty_impl<counter<i>> {
39 static constexpr auto apply(counter<i>) { return hana::false_c; }
45 // find_if and any_of should short-circuit and stop even though the
46 // Iterable is infinite.
47 BOOST_HANA_CONSTANT_CHECK(hana::any_of(counter<1>{}, hana::equal.to(hana::int_c<4>)));
49 BOOST_HANA_CONSTANT_CHECK(hana::equal(
50 hana::find_if(counter<1>{}, hana::equal.to(hana::int_c<4>)),
51 hana::just(hana::int_c<4>)