ceph/src/boost/libs/hana/example/sort.cpp

   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)
   4
   5 #include <boost/hana/assert.hpp>
   6 #include <boost/hana/equal.hpp>
   7 #include <boost/hana/front.hpp>
   8 #include <boost/hana/greater.hpp>
   9 #include <boost/hana/integral_constant.hpp>
  10 #include <boost/hana/negate.hpp>
  11 #include <boost/hana/ordering.hpp>
  12 #include <boost/hana/sort.hpp>
  13 #include <boost/hana/tuple.hpp>
  14
  15 #include <string>
  16 namespace hana = boost::hana;
  17 using namespace hana::literals;
  18 using namespace std::literals;
  19
  20
  21 // sort without a predicate
  22 BOOST_HANA_CONSTANT_CHECK(
  23     hana::sort(hana::make_tuple(1_c, -2_c, 3_c, 0_c)) ==
  24                hana::make_tuple(-2_c, 0_c, 1_c, 3_c)
  25 );
  26
  27 // sort with a predicate
  28 BOOST_HANA_CONSTANT_CHECK(
  29     hana::sort(hana::make_tuple(1_c, -2_c, 3_c, 0_c), hana::greater) ==
  30                hana::make_tuple(3_c, 1_c, 0_c, -2_c)
  31 );
  32
  33 int main() {
  34     // sort.by is syntactic sugar
  35     auto tuples = hana::make_tuple(
  36         hana::make_tuple(2_c, 'x', nullptr),
  37         hana::make_tuple(1_c, "foobar"s, hana::int_c<4>)
  38     );
  39
  40     BOOST_HANA_RUNTIME_CHECK(
  41         hana::sort.by(hana::ordering(hana::front), tuples)
  42             == hana::make_tuple(
  43                 hana::make_tuple(1_c, "foobar"s, hana::int_c<4>),
  44                 hana::make_tuple(2_c, 'x', nullptr)
  45             )
  46     );
  47 }