ceph/src/boost/boost/utility/ostream_string.hpp

   1 /*
   2 Copyright 2019 Glen Joseph Fernandes
   3 (glenjofe@gmail.com)
   4
   5 Distributed under the Boost Software License, Version 1.0.
   6 (http://www.boost.org/LICENSE_1_0.txt)
   7 */
   8 #ifndef BOOST_UTILITY_OSTREAM_STRING_HPP
   9 #define BOOST_UTILITY_OSTREAM_STRING_HPP
  10
  11 #include <boost/config.hpp>
  12 #include <iosfwd>
  13 #include <cstddef>
  14
  15 namespace boost {
  16 namespace detail {
  17
  18 template<class charT, class traits>
  19 inline std::size_t
  20 oss_put(std::basic_ostream<charT, traits>& os, const charT* data,
  21     std::size_t size)
  22 {
  23     return static_cast<std::size_t>(os.rdbuf()->sputn(data, size));
  24 }
  25
  26 template<class charT, class traits>
  27 inline bool
  28 oss_fill(std::basic_ostream<charT, traits>& os, std::size_t size)
  29 {
  30     charT c = os.fill();
  31     charT fill[] = { c, c, c, c, c, c, c, c };
  32     enum {
  33         chunk = sizeof fill / sizeof(charT)
  34     };
  35     for (; size > chunk; size -= chunk) {
  36         if (boost::detail::oss_put(os, fill, chunk) != chunk) {
  37             return false;
  38         }
  39     }
  40     return boost::detail::oss_put(os, fill, size) == size;
  41 }
  42
  43 template<class charT, class traits>
  44 class oss_guard {
  45 public:
  46     explicit oss_guard(std::basic_ostream<charT, traits>& os) BOOST_NOEXCEPT
  47         : os_(&os) { }
  48     ~oss_guard() BOOST_NOEXCEPT_IF(false) {
  49         if (os_) {
  50             os_->setstate(std::basic_ostream<charT, traits>::badbit);
  51         }
  52     }
  53     void release() BOOST_NOEXCEPT {
  54         os_ = 0;
  55     }
  56 private:
  57     oss_guard(const oss_guard&);
  58     oss_guard& operator=(const oss_guard&);
  59     std::basic_ostream<charT, traits>* os_;
  60 };
  61
  62 } /* detail */
  63
  64 template<class charT, class traits>
  65 inline std::basic_ostream<charT, traits>&
  66 ostream_string(std::basic_ostream<charT, traits>& os, const charT* data,
  67     std::size_t size)
  68 {
  69     typedef std::basic_ostream<charT, traits> stream;
  70     detail::oss_guard<charT, traits> guard(os);
  71     typename stream::sentry entry(os);
  72     if (entry) {
  73         std::size_t width = static_cast<std::size_t>(os.width());
  74         if (width <= size) {
  75             if (detail::oss_put(os, data, size) != size) {
  76                 return os;
  77             }
  78         } else if ((os.flags() & stream::adjustfield) == stream::left) {
  79             if (detail::oss_put(os, data, size) != size ||
  80                 !detail::oss_fill(os, width - size)) {
  81                 return os;
  82             }
  83         } else if (!detail::oss_fill(os, width - size) ||
  84             detail::oss_put(os, data, size) != size) {
  85             return os;
  86         }
  87         os.width(0);
  88     }
  89     guard.release();
  90     return os;
  91 }
  92
  93 } /* boost */
  94
  95 #endif