ceph/src/boost/libs/hana/test/integral_constant/hash.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/bool.hpp>
   7 #include <boost/hana/config.hpp>
   8 #include <boost/hana/equal.hpp>
   9 #include <boost/hana/hash.hpp>
  10 #include <boost/hana/integral_constant.hpp>
  11 #include <boost/hana/type.hpp>
  12
  13 #include <type_traits>
  14 namespace hana = boost::hana;
  15
  16
  17 int main() {
  18     // Unsigned integral constants should hash to `unsigned long long`
  19     {
  20         BOOST_HANA_CONSTANT_ASSERT(hana::equal(
  21             hana::hash(hana::integral_c<unsigned char, 10>),
  22             hana::type_c<hana::integral_constant<unsigned long long, 10>>
  23         ));
  24         BOOST_HANA_CONSTANT_ASSERT(hana::equal(
  25             hana::hash(hana::integral_c<unsigned short, 10>),
  26             hana::type_c<hana::integral_constant<unsigned long long, 10>>
  27         ));
  28         BOOST_HANA_CONSTANT_ASSERT(hana::equal(
  29             hana::hash(hana::integral_c<unsigned int, 10>),
  30             hana::type_c<hana::integral_constant<unsigned long long, 10>>
  31         ));
  32         BOOST_HANA_CONSTANT_ASSERT(hana::equal(
  33             hana::hash(hana::integral_c<unsigned long, 10>),
  34             hana::type_c<hana::integral_constant<unsigned long long, 10>>
  35         ));
  36         BOOST_HANA_CONSTANT_ASSERT(hana::equal(
  37             hana::hash(hana::integral_c<unsigned long long, 10>),
  38             hana::type_c<hana::integral_constant<unsigned long long, 10>>
  39         ));
  40     }
  41
  42     // Signed integral constants should hash to `signed long long`
  43     {
  44         BOOST_HANA_CONSTANT_ASSERT(hana::equal(
  45             hana::hash(hana::integral_c<signed char, 10>),
  46             hana::type_c<hana::integral_constant<signed long long, 10>>
  47         ));
  48         BOOST_HANA_CONSTANT_ASSERT(hana::equal(
  49             hana::hash(hana::integral_c<signed short, 10>),
  50             hana::type_c<hana::integral_constant<signed long long, 10>>
  51         ));
  52         BOOST_HANA_CONSTANT_ASSERT(hana::equal(
  53             hana::hash(hana::integral_c<signed int, 10>),
  54             hana::type_c<hana::integral_constant<signed long long, 10>>
  55         ));
  56         BOOST_HANA_CONSTANT_ASSERT(hana::equal(
  57             hana::hash(hana::integral_c<signed long, 10>),
  58             hana::type_c<hana::integral_constant<signed long long, 10>>
  59         ));
  60         BOOST_HANA_CONSTANT_ASSERT(hana::equal(
  61             hana::hash(hana::integral_c<signed long long, 10>),
  62             hana::type_c<hana::integral_constant<signed long long, 10>>
  63         ));
  64     }
  65
  66     // `char` should hash to either `signed long long` or `unsigned long long`,
  67     // depending on its signedness
  68     {
  69         using T = std::conditional_t<
  70             std::is_signed<char>::value,
  71             signed long long,
  72             unsigned long long
  73         >;
  74
  75         BOOST_HANA_CONSTANT_ASSERT(hana::equal(
  76             hana::hash(hana::integral_c<char, 10>),
  77             hana::type_c<hana::integral_constant<T, 10>>
  78         ));
  79     }
  80
  81     // Pointers to members should hash to themselves.
  82     // This test is disabled in pre-C++17, because pointers to non-static
  83     // data members can't be used as non-type template arguments before that.
  84     // See http://stackoverflow.com/q/35398848/627587.
  85     {
  86 #if __cplusplus > 201402L
  87
  88         struct Foo { int bar; };
  89         constexpr auto x = hana::integral_constant<int Foo::*, &Foo::bar>{};
  90         BOOST_HANA_CONSTANT_ASSERT(hana::equal(
  91             hana::hash(x),
  92             hana::type_c<hana::integral_constant<int Foo::*, &Foo::bar>>
  93         ));
  94
  95 #endif
  96     }
  97
  98     // Booleans should hash to themselves
  99     {
 100         BOOST_HANA_CONSTANT_ASSERT(hana::equal(
 101             hana::hash(hana::true_c),
 102             hana::type_c<hana::true_>
 103         ));
 104
 105         BOOST_HANA_CONSTANT_ASSERT(hana::equal(
 106             hana::hash(hana::false_c),
 107             hana::type_c<hana::false_>
 108         ));
 109     }
 110 }