ceph/src/boost/libs/leaf/test/defer_nested_error_result_test.cpp

   1 // Copyright 2018-2022 Emil Dotchevski and Reverge Studios, Inc.
   2
   3 // Distributed under the Boost Software License, Version 1.0. (See accompanying
   4 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   5
   6 #ifdef BOOST_LEAF_TEST_SINGLE_HEADER
   7 #   include "leaf.hpp"
   8 #else
   9 #   include <boost/leaf/on_error.hpp>
  10 #   include <boost/leaf/handle_errors.hpp>
  11 #   include <boost/leaf/result.hpp>
  12 #endif
  13
  14 #include "lightweight_test.hpp"
  15
  16 namespace leaf = boost::leaf;
  17
  18 template <int>
  19 struct info
  20 {
  21     int value;
  22 };
  23
  24 leaf::error_id f0()
  25 {
  26     auto load = leaf::on_error( [] { return info<0>{0}; } );
  27     return leaf::new_error( info<2>{2} );
  28 }
  29
  30 leaf::error_id f1()
  31 {
  32     auto load = leaf::on_error( [] { return info<0>{-1}; }, [] { return info<1>{1}; }, [] { return info<2>{-1}; } );
  33     return f0();
  34 }
  35
  36 leaf::error_id f2()
  37 {
  38     return f1().load( info<3>{3} );
  39 }
  40
  41 int main()
  42 {
  43     int r = leaf::try_handle_all(
  44         []() -> leaf::result<int>
  45         {
  46             return f2();
  47         },
  48         []( info<0> i0, info<1> i1, info<2> i2, info<3> i3 )
  49         {
  50             BOOST_TEST_EQ(i0.value, 0);
  51             BOOST_TEST_EQ(i1.value, 1);
  52             BOOST_TEST_EQ(i2.value, 2);
  53             BOOST_TEST_EQ(i3.value, 3);
  54             return 1;
  55         },
  56         []
  57         {
  58             return 2;
  59         } );
  60     BOOST_TEST_EQ(r, 1);
  61
  62     return boost::report_errors();
  63 }