ceph/src/boost/libs/hana/test/repeat.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/fwd/concept/integral_constant.hpp>
   7 #include <boost/hana/repeat.hpp>
   8 namespace hana = boost::hana;
   9
  10
  11 //////////////////////////////////////////////////////////////////////////////
  12 // Define a simple model of IntegralConstant for use below
  13 template <int i>
  14 struct constant {
  15     static constexpr int value = i;
  16     using value_type = int;
  17 };
  18
  19 namespace boost { namespace hana {
  20     template <int i>
  21     struct IntegralConstant<constant<i>> {
  22         static constexpr bool value = true;
  23     };
  24
  25     // definition of `to<>` omitted
  26 }}
  27 //////////////////////////////////////////////////////////////////////////////
  28
  29 void function() { }
  30
  31 int main() {
  32     int counter = 0;
  33     hana::repeat(constant<3>{}, [&] { ++counter; });
  34     BOOST_HANA_RUNTIME_CHECK(counter == 3);
  35
  36     // Try with a normal function.
  37     hana::repeat(constant<3>{}, function);
  38
  39     // Try with a function pointer.
  40     hana::repeat(constant<3>{}, static_cast<void(*)()>(function));
  41
  42     // Make sure we don't read from a non-constexpr variable.
  43     constant<3> three{};
  44     hana::repeat(three, []{});
  45 }