ceph/src/boost/libs/yap/test/compile_is_expr.cpp

   1 // Copyright (C) 2016-2018 T. Zachary Laine
   2 //
   3 // Distributed under the Boost Software License, Version 1.0. (See
   4 // accompanying file LICENSE_1_0.txt or copy at
   5 // http://www.boost.org/LICENSE_1_0.txt)
   6 #include <boost/yap/expression.hpp>
   7
   8
   9 namespace yap = boost::yap;
  10
  11 struct alternate_expr_1
  12 {
  13     static const yap::expr_kind kind = yap::expr_kind::plus;
  14     boost::hana::tuple<> elements;
  15 };
  16
  17 struct alternate_expr_2
  18 {
  19     static const yap::expr_kind kind = yap::expr_kind::plus;
  20     boost::hana::tuple<int, double> elements;
  21 };
  22
  23
  24 struct non_expr_1
  25 {};
  26
  27 struct non_expr_2
  28 {
  29     boost::hana::tuple<int, double> elements;
  30 };
  31
  32 struct non_expr_3
  33 {
  34     static const int kind = 0;
  35     boost::hana::tuple<int, double> elements;
  36 };
  37
  38 struct non_expr_4
  39 {
  40     int kind;
  41     boost::hana::tuple<int, double> elements;
  42 };
  43
  44 struct non_expr_5
  45 {
  46     static const yap::expr_kind kind = yap::expr_kind::plus;
  47 };
  48
  49 struct non_expr_6
  50 {
  51     static const yap::expr_kind kind = yap::expr_kind::plus;
  52     int elements;
  53 };
  54
  55
  56 void compile_is_expr()
  57 {
  58     static_assert(
  59         yap::is_expr<yap::terminal<yap::expression, double>>::value, "");
  60
  61     static_assert(
  62         yap::is_expr<yap::terminal<yap::expression, double> const>::value, "");
  63     static_assert(
  64         yap::is_expr<yap::terminal<yap::expression, double> const &>::value,
  65         "");
  66     static_assert(
  67         yap::is_expr<yap::terminal<yap::expression, double> &>::value, "");
  68     static_assert(
  69         yap::is_expr<yap::terminal<yap::expression, double> &&>::value, "");
  70
  71     {
  72         using namespace yap::literals;
  73         static_assert(yap::is_expr<decltype(1_p)>::value, "");
  74     }
  75
  76     static_assert(
  77         yap::is_expr<yap::expression<
  78             yap::expr_kind::unary_plus,
  79             boost::hana::tuple<yap::terminal<yap::expression, double>>>>::value,
  80         "");
  81     static_assert(
  82         yap::is_expr<yap::expression<
  83             yap::expr_kind::plus,
  84             boost::hana::tuple<
  85                 yap::terminal<yap::expression, double>,
  86                 yap::terminal<yap::expression, double>>>>::value,
  87         "");
  88
  89     static_assert(yap::is_expr<alternate_expr_1>::value, "");
  90     static_assert(yap::is_expr<alternate_expr_2>::value, "");
  91
  92     static_assert(!yap::is_expr<int>::value, "");
  93     static_assert(!yap::is_expr<non_expr_1>::value, "");
  94     static_assert(!yap::is_expr<non_expr_2>::value, "");
  95     static_assert(!yap::is_expr<non_expr_3>::value, "");
  96     static_assert(!yap::is_expr<non_expr_4>::value, "");
  97     static_assert(!yap::is_expr<non_expr_5>::value, "");
  98     static_assert(!yap::is_expr<non_expr_6>::value, "");
  99 }