ceph/src/boost/boost/histogram/literals.hpp

   1 // Copyright 2015-2017 Hans Dembinski
   2 //
   3 // Distributed under the Boost Software License, Version 1.0.
   4 // (See accompanying file LICENSE_1_0.txt
   5 // or copy at http://www.boost.org/LICENSE_1_0.txt)
   6
   7 #ifndef BOOST_HISTOGRAM_LITERALS_HPP
   8 #define BOOST_HISTOGRAM_LITERALS_HPP
   9
  10 #include <type_traits>
  11
  12 namespace boost {
  13 namespace histogram {
  14 namespace detail {
  15 constexpr unsigned parse_number(unsigned n) { return n; }
  16
  17 template <class... Rest>
  18 constexpr unsigned parse_number(unsigned n, char f, Rest... rest) {
  19   return parse_number(10u * n + static_cast<unsigned>(f - '0'), rest...);
  20 }
  21 } // namespace detail
  22
  23 namespace literals {
  24 /// Suffix operator to generate literal compile-time numbers, 0_c, 12_c, etc.
  25 template <char... digits>
  26 auto operator"" _c() {
  27   return std::integral_constant<unsigned, detail::parse_number(0, digits...)>();
  28 }
  29 } // namespace literals
  30 } // namespace histogram
  31 } // namespace boost
  32
  33 #endif