ceph/src/boost/libs/leaf/test/BOOST_LEAF_AUTO_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/result.hpp>
  10 #   include <boost/leaf/handle_errors.hpp>
  11 #endif
  12
  13 #include "lightweight_test.hpp"
  14 #ifdef BOOST_LEAF_BOOST_AVAILABLE
  15 #   include <boost/config/workaround.hpp>
  16 #else
  17 #   define BOOST_WORKAROUND(a,b) 0
  18 #endif
  19
  20 namespace leaf = boost::leaf;
  21
  22 struct value
  23 {
  24     int x;
  25
  26     explicit value( int x ): x(x) { };
  27
  28 #ifndef BOOST_LEAF_NO_CXX11_REF_QUALIFIERS
  29     value( value const & ) = delete;
  30     value( value && ) = default;
  31 #endif
  32 };
  33
  34 leaf::result<value> f1()
  35 {
  36     return value { 21 };
  37 }
  38
  39 leaf::result<value> f2()
  40 {
  41     BOOST_LEAF_AUTO(a, f1());
  42 #if BOOST_WORKAROUND( BOOST_GCC, < 50000 ) || BOOST_WORKAROUND( BOOST_CLANG, <= 30800 )
  43     return std::move(a); // Older compilers are confused, but...
  44 #else
  45     return a; // ...this doesn't need to be return std::move(a);
  46 #endif
  47 }
  48
  49 template <class Lambda>
  50 leaf::result<value> f2_lambda( Lambda )
  51 {
  52     BOOST_LEAF_AUTO(a, f1());
  53 #if BOOST_WORKAROUND( BOOST_GCC, < 50000 ) || BOOST_WORKAROUND( BOOST_CLANG, <= 30800 )
  54     return std::move(a); // Older compilers are confused, but...
  55 #else
  56     return a; // ...this doesn't need to be return std::move(a);
  57 #endif
  58 }
  59
  60 leaf::result<value> f3()
  61 {
  62     BOOST_LEAF_AUTO(a, f2());
  63
  64     // Invoking the macro twice in the same scope, testing the temp name
  65     // generation. Also making sure we can pass a lambda (See
  66     // https://github.com/boostorg/leaf/issues/16).
  67     BOOST_LEAF_AUTO(b, f2_lambda([]{}));
  68
  69     return value { a.x + b.x };
  70 }
  71
  72 int main()
  73 {
  74     BOOST_TEST_EQ(f3()->x, 42);
  75
  76     {
  77         int r = leaf::try_handle_all(
  78             []() -> leaf::result<int>
  79             {
  80                 int x = 42;
  81
  82                 leaf::result<int> r1(x);
  83                 BOOST_LEAF_AUTO(rx1, r1);
  84                 BOOST_TEST_EQ(r1.value(), rx1);
  85
  86                 leaf::result<int &> r2(x);
  87                 BOOST_LEAF_AUTO(rx2, r2);
  88                 BOOST_TEST_EQ(r2.value(), rx2);
  89
  90                 return 0;
  91             },
  92             []
  93             {
  94                 return 1;
  95             } );
  96         BOOST_TEST_EQ(r, 0);
  97     }
  98
  99     return boost::report_errors();
 100 }