ceph/src/boost/libs/hof/test/issue8.cpp

   1 /*=============================================================================
   2     Copyright (c) 2017 Paul Fultz II
   3     issue8.cpp
   4     Distributed under the Boost Software License, Version 1.0. (See accompanying
   5     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   6 ==============================================================================*/
   7
   8 #include "test.hpp"
   9 #include <vector>
  10 #include <boost/hof/pipable.hpp>
  11 #include <boost/hof/placeholders.hpp>
  12 #include <algorithm>
  13
  14
  15 struct filter_fn
  16 {
  17     template<class Input, class P>
  18     Input operator()(Input input, P pred) const
  19     {
  20         Input output(input.size());
  21         output.erase(
  22             ::std::copy_if(
  23                 ::std::begin(input),
  24                 ::std::end(input),
  25                 ::std::begin(output),
  26                 pred
  27             ),
  28             ::std::end(output)
  29         );
  30         return output;
  31     }
  32 };
  33
  34 static constexpr boost::hof::pipable_adaptor<filter_fn> filter = {};
  35
  36 BOOST_HOF_TEST_CASE()
  37 {
  38     std::vector<int> data;
  39     for(int i=0;i<6;i++)
  40     {
  41         data.push_back(i);
  42     }
  43     std::vector<int> r1 = data | filter(boost::hof::_1 > 1);
  44     BOOST_HOF_TEST_CHECK(r1.size() == 4);
  45
  46     std::vector<int> r2 = filter(data, boost::hof::_1 > 1);
  47     BOOST_HOF_TEST_CHECK(r2.size() == 4);
  48 }