Blame view

3rdparty/boost_1_81_0/libs/hana/example/span.cpp 1.29 KB
73ef4ff3   Hu Chunming   提交三方库
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
  // Copyright Louis Dionne 2013-2022
  // Distributed under the Boost Software License, Version 1.0.
  // (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
  
  #include <boost/hana/assert.hpp>
  #include <boost/hana/equal.hpp>
  #include <boost/hana/integral_constant.hpp>
  #include <boost/hana/less.hpp>
  #include <boost/hana/pair.hpp>
  #include <boost/hana/span.hpp>
  #include <boost/hana/tuple.hpp>
  namespace hana = boost::hana;
  
  
  constexpr auto xs = hana::make_tuple(hana::int_c<1>, hana::int_c<2>, hana::int_c<3>, hana::int_c<4>);
  
  BOOST_HANA_CONSTANT_CHECK(
      hana::span(xs, hana::less.than(hana::int_c<3>))
      ==
      hana::make_pair(hana::make_tuple(hana::int_c<1>, hana::int_c<2>),
                      hana::make_tuple(hana::int_c<3>, hana::int_c<4>))
  );
  
  BOOST_HANA_CONSTANT_CHECK(
      hana::span(xs, hana::less.than(hana::int_c<0>))
      ==
      hana::make_pair(hana::make_tuple(), xs)
  );
  
  BOOST_HANA_CONSTANT_CHECK(
      hana::span(xs, hana::less.than(hana::int_c<5>))
      ==
      hana::make_pair(xs, hana::make_tuple())
  );
  
  // span.by is syntactic sugar
  BOOST_HANA_CONSTANT_CHECK(
      hana::span.by(hana::less.than(hana::int_c<3>), xs)
      ==
      hana::make_pair(hana::make_tuple(hana::int_c<1>, hana::int_c<2>),
                      hana::make_tuple(hana::int_c<3>, hana::int_c<4>))
  );
  
  int main() { }