ceph/src/boost/boost/pfr/detail/io.hpp

   1 // Copyright (c) 2016-2022 Antony Polukhin
   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 #ifndef BOOST_PFR_DETAIL_IO_HPP
   7 #define BOOST_PFR_DETAIL_IO_HPP
   8 #pragma once
   9
  10 #include <boost/pfr/detail/config.hpp>
  11
  12 #include <boost/pfr/detail/sequence_tuple.hpp>
  13 #include <iosfwd>       // stream operators
  14 #include <iomanip>
  15
  16 #if defined(__has_include)
  17 #   if __has_include(<string_view>) && BOOST_PFR_USE_CPP17
  18 #       include <string_view>
  19 #   endif
  20 #endif
  21
  22 namespace boost { namespace pfr { namespace detail {
  23
  24 inline auto quoted_helper(const std::string& s) noexcept {
  25     return std::quoted(s);
  26 }
  27
  28 #if defined(__has_include)
  29 #   if __has_include(<string_view>) && BOOST_PFR_USE_CPP17
  30 template <class CharT, class Traits>
  31 inline auto quoted_helper(std::basic_string_view<CharT, Traits> s) noexcept {
  32     return std::quoted(s);
  33 }
  34 #   endif
  35 #endif
  36
  37 inline auto quoted_helper(std::string& s) noexcept {
  38     return std::quoted(s);
  39 }
  40
  41 template <class T>
  42 inline decltype(auto) quoted_helper(T&& v) noexcept {
  43     return std::forward<T>(v);
  44 }
  45
  46 template <std::size_t I, std::size_t N>
  47 struct print_impl {
  48     template <class Stream, class T>
  49     static void print (Stream& out, const T& value) {
  50         if (!!I) out << ", ";
  51         out << detail::quoted_helper(boost::pfr::detail::sequence_tuple::get<I>(value));
  52         print_impl<I + 1, N>::print(out, value);
  53     }
  54 };
  55
  56 template <std::size_t I>
  57 struct print_impl<I, I> {
  58     template <class Stream, class T> static void print (Stream&, const T&) noexcept {}
  59 };
  60
  61
  62 template <std::size_t I, std::size_t N>
  63 struct read_impl {
  64     template <class Stream, class T>
  65     static void read (Stream& in, const T& value) {
  66         char ignore = {};
  67         if (!!I) {
  68             in >> ignore;
  69             if (ignore != ',') in.setstate(Stream::failbit);
  70             in >> ignore;
  71             if (ignore != ' ')  in.setstate(Stream::failbit);
  72         }
  73         in >> detail::quoted_helper( boost::pfr::detail::sequence_tuple::get<I>(value) );
  74         read_impl<I + 1, N>::read(in, value);
  75     }
  76 };
  77
  78 template <std::size_t I>
  79 struct read_impl<I, I> {
  80     template <class Stream, class T> static void read (Stream&, const T&) {}
  81 };
  82
  83 }}} // namespace boost::pfr::detail
  84
  85 #endif // BOOST_PFR_DETAIL_IO_HPP