3rdparty/boost/boost/lexical_cast/detail/converter_lexical_streams.hpp

   1 // Copyright Kevlin Henney, 2000-2005.
   2 // Copyright Alexander Nasonov, 2006-2010.
   3 // Copyright Antony Polukhin, 2011-2019.
   4 //
   5 // Distributed under the Boost Software License, Version 1.0. (See
   6 // accompanying file LICENSE_1_0.txt or copy at
   7 // http://www.boost.org/LICENSE_1_0.txt)
   8 //
   9 // what:  lexical_cast custom keyword cast
  10 // who:   contributed by Kevlin Henney,
  11 //        enhanced with contributions from Terje Slettebo,
  12 //        with additional fixes and suggestions from Gennaro Prota,
  13 //        Beman Dawes, Dave Abrahams, Daryle Walker, Peter Dimov,
  14 //        Alexander Nasonov, Antony Polukhin, Justin Viiret, Michael Hofmann,
  15 //        Cheng Yang, Matthew Bradbury, David W. Birdsall, Pavel Korzh and other Boosters
  16 // when:  November 2000, March 2003, June 2005, June 2006, March 2011 - 2014, Nowember 2016
  17
  18 #ifndef BOOST_LEXICAL_CAST_DETAIL_CONVERTER_LEXICAL_STREAMS_HPP
  19 #define BOOST_LEXICAL_CAST_DETAIL_CONVERTER_LEXICAL_STREAMS_HPP
  20
  21 #include <boost/config.hpp>
  22 #ifdef BOOST_HAS_PRAGMA_ONCE
  23 #   pragma once
  24 #endif
  25
  26
  27 #if defined(BOOST_NO_STRINGSTREAM) || defined(BOOST_NO_STD_WSTRING)
  28 #define BOOST_LCAST_NO_WCHAR_T
  29 #endif
  30
  31 #include <cstddef>
  32 #include <string>
  33 #include <cstring>
  34 #include <cstdio>
  35 #include <boost/limits.hpp>
  36 #include <boost/type_traits/conditional.hpp>
  37 #include <boost/type_traits/is_pointer.hpp>
  38 #include <boost/static_assert.hpp>
  39 #include <boost/detail/workaround.hpp>
  40
  41
  42 #ifndef BOOST_NO_STD_LOCALE
  43 #   include <locale>
  44 #else
  45 #   ifndef BOOST_LEXICAL_CAST_ASSUME_C_LOCALE
  46         // Getting error at this point means, that your STL library is old/lame/misconfigured.
  47         // If nothing can be done with STL library, define BOOST_LEXICAL_CAST_ASSUME_C_LOCALE,
  48         // but beware: lexical_cast will understand only 'C' locale delimeters and thousands
  49         // separators.
  50 #       error "Unable to use <locale> header. Define BOOST_LEXICAL_CAST_ASSUME_C_LOCALE to force "
  51 #       error "boost::lexical_cast to use only 'C' locale during conversions."
  52 #   endif
  53 #endif
  54
  55 #ifdef BOOST_NO_STRINGSTREAM
  56 #include <strstream>
  57 #else
  58 #include <sstream>
  59 #endif
  60
  61 #include <boost/lexical_cast/detail/lcast_char_constants.hpp>
  62 #include <boost/lexical_cast/detail/lcast_unsigned_converters.hpp>
  63 #include <boost/lexical_cast/detail/inf_nan.hpp>
  64
  65 #include <istream>
  66
  67 #ifndef BOOST_NO_CXX11_HDR_ARRAY
  68 #include <array>
  69 #endif
  70
  71 #include <boost/array.hpp>
  72 #include <boost/type_traits/make_unsigned.hpp>
  73 #include <boost/type_traits/is_integral.hpp>
  74 #include <boost/type_traits/is_float.hpp>
  75 #include <boost/range/iterator_range_core.hpp>
  76 #include <boost/container/container_fwd.hpp>
  77 #include <boost/integer.hpp>
  78 #include <boost/detail/basic_pointerbuf.hpp>
  79 #include <boost/noncopyable.hpp>
  80 #ifndef BOOST_NO_CWCHAR
  81 #   include <cwchar>
  82 #endif
  83
  84 namespace boost {
  85
  86     namespace detail // basic_unlockedbuf
  87     {
  88         // acts as a stream buffer which wraps around a pair of pointers
  89         // and gives acces to internals
  90         template <class BufferType, class CharT>
  91         class basic_unlockedbuf : public basic_pointerbuf<CharT, BufferType> {
  92         public:
  93            typedef basic_pointerbuf<CharT, BufferType> base_type;
  94            typedef BOOST_DEDUCED_TYPENAME base_type::streamsize streamsize;
  95
  96 #ifndef BOOST_NO_USING_TEMPLATE
  97             using base_type::pptr;
  98             using base_type::pbase;
  99             using base_type::setbuf;
 100 #else
 101             charT* pptr() const { return base_type::pptr(); }
 102             charT* pbase() const { return base_type::pbase(); }
 103             BufferType* setbuf(char_type* s, streamsize n) { return base_type::setbuf(s, n); }
 104 #endif
 105         };
 106     }
 107
 108     namespace detail
 109     {
 110         struct do_not_construct_out_buffer_t{};
 111         struct do_not_construct_out_stream_t{
 112             do_not_construct_out_stream_t(do_not_construct_out_buffer_t*){}
 113         };
 114
 115         template <class CharT, class Traits>
 116         struct out_stream_helper_trait {
 117 #if defined(BOOST_NO_STRINGSTREAM)
 118             typedef std::ostream                                                    out_stream_t;
 119             typedef basic_unlockedbuf<std::strstreambuf, char>                      stringbuffer_t;
 120 #elif defined(BOOST_NO_STD_LOCALE)
 121             typedef std::ostream                                                    out_stream_t;
 122             typedef basic_unlockedbuf<std::stringbuf, char>                         stringbuffer_t;
 123             typedef basic_unlockedbuf<std::streambuf, char>                         buffer_t;
 124 #else
 125             typedef std::basic_ostream<CharT, Traits>                               out_stream_t;
 126             typedef basic_unlockedbuf<std::basic_stringbuf<CharT, Traits>, CharT>   stringbuffer_t;
 127             typedef basic_unlockedbuf<std::basic_streambuf<CharT, Traits>, CharT>   buffer_t;
 128 #endif
 129         };
 130     }
 131
 132     namespace detail // optimized stream wrappers
 133     {
 134         template< class CharT // a result of widest_char transformation
 135                 , class Traits
 136                 , bool RequiresStringbuffer
 137                 , std::size_t CharacterBufferSize
 138                 >
 139         class lexical_istream_limited_src: boost::noncopyable {
 140             typedef BOOST_DEDUCED_TYPENAME boost::conditional<
 141                 RequiresStringbuffer,
 142                 BOOST_DEDUCED_TYPENAME out_stream_helper_trait<CharT, Traits>::out_stream_t,
 143                 do_not_construct_out_stream_t
 144             >::type deduced_out_stream_t;
 145
 146             typedef BOOST_DEDUCED_TYPENAME boost::conditional<
 147                 RequiresStringbuffer,
 148                 BOOST_DEDUCED_TYPENAME out_stream_helper_trait<CharT, Traits>::stringbuffer_t,
 149                 do_not_construct_out_buffer_t
 150             >::type deduced_out_buffer_t;
 151
 152             deduced_out_buffer_t out_buffer;
 153             deduced_out_stream_t out_stream;
 154             CharT   buffer[CharacterBufferSize];
 155
 156             // After the `operator <<`  finishes, `[start, finish)` is
 157             // the range to output by `operator >>`
 158             const CharT*  start;
 159             const CharT*  finish;
 160
 161         public:
 162             lexical_istream_limited_src() BOOST_NOEXCEPT
 163               : out_buffer()
 164               , out_stream(&out_buffer)
 165               , start(buffer)
 166               , finish(buffer + CharacterBufferSize)
 167             {}
 168
 169             const CharT* cbegin() const BOOST_NOEXCEPT {
 170                 return start;
 171             }
 172
 173             const CharT* cend() const BOOST_NOEXCEPT {
 174                 return finish;
 175             }
 176
 177         private:
 178 /************************************ HELPER FUNCTIONS FOR OPERATORS << ( ... ) ********************************/
 179             bool shl_char(CharT ch) BOOST_NOEXCEPT {
 180                 Traits::assign(buffer[0], ch);
 181                 finish = start + 1;
 182                 return true;
 183             }
 184
 185 #ifndef BOOST_LCAST_NO_WCHAR_T
 186             template <class T>
 187             bool shl_char(T ch) {
 188                 BOOST_STATIC_ASSERT_MSG(( sizeof(T) <= sizeof(CharT)) ,
 189                     "boost::lexical_cast does not support narrowing of char types."
 190                     "Use boost::locale instead" );
 191 #ifndef BOOST_LEXICAL_CAST_ASSUME_C_LOCALE
 192                 std::locale loc;
 193                 CharT const w = BOOST_USE_FACET(std::ctype<CharT>, loc).widen(ch);
 194 #else
 195                 CharT const w = static_cast<CharT>(ch);
 196 #endif
 197                 Traits::assign(buffer[0], w);
 198                 finish = start + 1;
 199                 return true;
 200             }
 201 #endif
 202
 203             bool shl_char_array(CharT const* str_value) BOOST_NOEXCEPT {
 204                 start = str_value;
 205                 finish = start + Traits::length(str_value);
 206                 return true;
 207             }
 208
 209             template <class T>
 210             bool shl_char_array(T const* str_value) {
 211                 BOOST_STATIC_ASSERT_MSG(( sizeof(T) <= sizeof(CharT)),
 212                     "boost::lexical_cast does not support narrowing of char types."
 213                     "Use boost::locale instead" );
 214                 return shl_input_streamable(str_value);
 215             }
 216
 217             bool shl_char_array_limited(CharT const* str, std::size_t max_size) BOOST_NOEXCEPT {
 218                 start = str;
 219                 finish = std::find(start, start + max_size, Traits::to_char_type(0));
 220                 return true;
 221             }
 222
 223             template<typename InputStreamable>
 224             bool shl_input_streamable(InputStreamable& input) {
 225 #if defined(BOOST_NO_STRINGSTREAM) || defined(BOOST_NO_STD_LOCALE)
 226                 // If you have compilation error at this point, than your STL library
 227                 // does not support such conversions. Try updating it.
 228                 BOOST_STATIC_ASSERT((boost::is_same<char, CharT>::value));
 229 #endif
 230
 231 #ifndef BOOST_NO_EXCEPTIONS
 232                 out_stream.exceptions(std::ios::badbit);
 233                 try {
 234 #endif
 235                 bool const result = !(out_stream << input).fail();
 236                 const deduced_out_buffer_t* const p = static_cast<deduced_out_buffer_t*>(
 237                     out_stream.rdbuf()
 238                 );
 239                 start = p->pbase();
 240                 finish = p->pptr();
 241                 return result;
 242 #ifndef BOOST_NO_EXCEPTIONS
 243                 } catch (const ::std::ios_base::failure& /*f*/) {
 244                     return false;
 245                 }
 246 #endif
 247             }
 248
 249             template <class T>
 250             inline bool shl_unsigned(const T n) {
 251                 CharT* tmp_finish = buffer + CharacterBufferSize;
 252                 start = lcast_put_unsigned<Traits, T, CharT>(n, tmp_finish).convert();
 253                 finish = tmp_finish;
 254                 return true;
 255             }
 256
 257             template <class T>
 258             inline bool shl_signed(const T n) {
 259                 CharT* tmp_finish = buffer + CharacterBufferSize;
 260                 typedef BOOST_DEDUCED_TYPENAME boost::make_unsigned<T>::type utype;
 261                 CharT* tmp_start = lcast_put_unsigned<Traits, utype, CharT>(lcast_to_unsigned(n), tmp_finish).convert();
 262                 if (n < 0) {
 263                     --tmp_start;
 264                     CharT const minus = lcast_char_constants<CharT>::minus;
 265                     Traits::assign(*tmp_start, minus);
 266                 }
 267                 start = tmp_start;
 268                 finish = tmp_finish;
 269                 return true;
 270             }
 271
 272             template <class T, class SomeCharT>
 273             bool shl_real_type(const T& val, SomeCharT* /*begin*/) {
 274                 lcast_set_precision(out_stream, &val);
 275                 return shl_input_streamable(val);
 276             }
 277
 278             bool shl_real_type(float val, char* begin) {
 279                 using namespace std;
 280                 const double val_as_double = val;
 281                 finish = start +
 282 #if defined(_MSC_VER) && (_MSC_VER >= 1400) && !defined(__SGI_STL_PORT) && !defined(_STLPORT_VERSION)
 283                     sprintf_s(begin, CharacterBufferSize,
 284 #else
 285                     sprintf(begin,
 286 #endif
 287                     "%.*g", static_cast<int>(boost::detail::lcast_get_precision<float>()), val_as_double);
 288                 return finish > start;
 289             }
 290
 291             bool shl_real_type(double val, char* begin) {
 292                 using namespace std;
 293                 finish = start +
 294 #if defined(_MSC_VER) && (_MSC_VER >= 1400) && !defined(__SGI_STL_PORT) && !defined(_STLPORT_VERSION)
 295                     sprintf_s(begin, CharacterBufferSize,
 296 #else
 297                     sprintf(begin,
 298 #endif
 299                     "%.*g", static_cast<int>(boost::detail::lcast_get_precision<double>()), val);
 300                 return finish > start;
 301             }
 302
 303 #ifndef __MINGW32__
 304             bool shl_real_type(long double val, char* begin) {
 305                 using namespace std;
 306                 finish = start +
 307 #if defined(_MSC_VER) && (_MSC_VER >= 1400) && !defined(__SGI_STL_PORT) && !defined(_STLPORT_VERSION)
 308                     sprintf_s(begin, CharacterBufferSize,
 309 #else
 310                     sprintf(begin,
 311 #endif
 312                     "%.*Lg", static_cast<int>(boost::detail::lcast_get_precision<long double>()), val );
 313                 return finish > start;
 314             }
 315 #endif
 316
 317
 318 #if !defined(BOOST_LCAST_NO_WCHAR_T) && !defined(BOOST_NO_SWPRINTF) && !defined(__MINGW32__)
 319             bool shl_real_type(float val, wchar_t* begin) {
 320                 using namespace std;
 321                 const double val_as_double = val;
 322                 finish = start + swprintf(begin, CharacterBufferSize,
 323                                        L"%.*g",
 324                                        static_cast<int>(boost::detail::lcast_get_precision<float >()),
 325                                        val_as_double );
 326                 return finish > start;
 327             }
 328
 329             bool shl_real_type(double val, wchar_t* begin) {
 330                 using namespace std;
 331                 finish = start + swprintf(begin, CharacterBufferSize,
 332                                           L"%.*g", static_cast<int>(boost::detail::lcast_get_precision<double >()), val );
 333                 return finish > start;
 334             }
 335
 336             bool shl_real_type(long double val, wchar_t* begin) {
 337                 using namespace std;
 338                 finish = start + swprintf(begin, CharacterBufferSize,
 339                                           L"%.*Lg", static_cast<int>(boost::detail::lcast_get_precision<long double >()), val );
 340                 return finish > start;
 341             }
 342 #endif
 343             template <class T>
 344             bool shl_real(T val) {
 345                 CharT* tmp_finish = buffer + CharacterBufferSize;
 346                 if (put_inf_nan(buffer, tmp_finish, val)) {
 347                     finish = tmp_finish;
 348                     return true;
 349                 }
 350
 351                 return shl_real_type(val, static_cast<CharT*>(buffer));
 352             }
 353
 354 /************************************ OPERATORS << ( ... ) ********************************/
 355         public:
 356             template<class Alloc>
 357             bool operator<<(std::basic_string<CharT,Traits,Alloc> const& str) BOOST_NOEXCEPT {
 358                 start = str.data();
 359                 finish = start + str.length();
 360                 return true;
 361             }
 362
 363             template<class Alloc>
 364             bool operator<<(boost::container::basic_string<CharT,Traits,Alloc> const& str) BOOST_NOEXCEPT {
 365                 start = str.data();
 366                 finish = start + str.length();
 367                 return true;
 368             }
 369
 370             bool operator<<(bool value) BOOST_NOEXCEPT {
 371                 CharT const czero = lcast_char_constants<CharT>::zero;
 372                 Traits::assign(buffer[0], Traits::to_char_type(czero + value));
 373                 finish = start + 1;
 374                 return true;
 375             }
 376
 377             template <class C>
 378             BOOST_DEDUCED_TYPENAME boost::disable_if<boost::is_const<C>, bool>::type
 379             operator<<(const iterator_range<C*>& rng) BOOST_NOEXCEPT {
 380                 return (*this) << iterator_range<const C*>(rng.begin(), rng.end());
 381             }
 382
 383             bool operator<<(const iterator_range<const CharT*>& rng) BOOST_NOEXCEPT {
 384                 start = rng.begin();
 385                 finish = rng.end();
 386                 return true;
 387             }
 388
 389             bool operator<<(const iterator_range<const signed char*>& rng) BOOST_NOEXCEPT {
 390                 return (*this) << iterator_range<const char*>(
 391                     reinterpret_cast<const char*>(rng.begin()),
 392                     reinterpret_cast<const char*>(rng.end())
 393                 );
 394             }
 395
 396             bool operator<<(const iterator_range<const unsigned char*>& rng) BOOST_NOEXCEPT {
 397                 return (*this) << iterator_range<const char*>(
 398                     reinterpret_cast<const char*>(rng.begin()),
 399                     reinterpret_cast<const char*>(rng.end())
 400                 );
 401             }
 402
 403             bool operator<<(char ch)                    { return shl_char(ch); }
 404             bool operator<<(unsigned char ch)           { return ((*this) << static_cast<char>(ch)); }
 405             bool operator<<(signed char ch)             { return ((*this) << static_cast<char>(ch)); }
 406 #if !defined(BOOST_LCAST_NO_WCHAR_T)
 407             bool operator<<(wchar_t const* str)         { return shl_char_array(str); }
 408             bool operator<<(wchar_t * str)              { return shl_char_array(str); }
 409 #ifndef BOOST_NO_INTRINSIC_WCHAR_T
 410             bool operator<<(wchar_t ch)                 { return shl_char(ch); }
 411 #endif
 412 #endif
 413 #if !defined(BOOST_NO_CXX11_CHAR16_T) && !defined(BOOST_NO_CXX11_UNICODE_LITERALS)
 414             bool operator<<(char16_t ch)                { return shl_char(ch); }
 415             bool operator<<(char16_t * str)             { return shl_char_array(str); }
 416             bool operator<<(char16_t const * str)       { return shl_char_array(str); }
 417 #endif
 418 #if !defined(BOOST_NO_CXX11_CHAR32_T) && !defined(BOOST_NO_CXX11_UNICODE_LITERALS)
 419             bool operator<<(char32_t ch)                { return shl_char(ch); }
 420             bool operator<<(char32_t * str)             { return shl_char_array(str); }
 421             bool operator<<(char32_t const * str)       { return shl_char_array(str); }
 422 #endif
 423             bool operator<<(unsigned char const* ch)    { return ((*this) << reinterpret_cast<char const*>(ch)); }
 424             bool operator<<(unsigned char * ch)         { return ((*this) << reinterpret_cast<char *>(ch)); }
 425             bool operator<<(signed char const* ch)      { return ((*this) << reinterpret_cast<char const*>(ch)); }
 426             bool operator<<(signed char * ch)           { return ((*this) << reinterpret_cast<char *>(ch)); }
 427             bool operator<<(char const* str_value)      { return shl_char_array(str_value); }
 428             bool operator<<(char* str_value)            { return shl_char_array(str_value); }
 429             bool operator<<(short n)                    { return shl_signed(n); }
 430             bool operator<<(int n)                      { return shl_signed(n); }
 431             bool operator<<(long n)                     { return shl_signed(n); }
 432             bool operator<<(unsigned short n)           { return shl_unsigned(n); }
 433             bool operator<<(unsigned int n)             { return shl_unsigned(n); }
 434             bool operator<<(unsigned long n)            { return shl_unsigned(n); }
 435
 436 #if defined(BOOST_HAS_LONG_LONG)
 437             bool operator<<(boost::ulong_long_type n)   { return shl_unsigned(n); }
 438             bool operator<<(boost::long_long_type n)    { return shl_signed(n); }
 439 #elif defined(BOOST_HAS_MS_INT64)
 440             bool operator<<(unsigned __int64 n)         { return shl_unsigned(n); }
 441             bool operator<<(         __int64 n)         { return shl_signed(n); }
 442 #endif
 443
 444 #ifdef BOOST_HAS_INT128
 445             bool operator<<(const boost::uint128_type& n)   { return shl_unsigned(n); }
 446             bool operator<<(const boost::int128_type& n)    { return shl_signed(n); }
 447 #endif
 448             bool operator<<(float val)                  { return shl_real(val); }
 449             bool operator<<(double val)                 { return shl_real(val); }
 450             bool operator<<(long double val)            {
 451 #ifndef __MINGW32__
 452                 return shl_real(val);
 453 #else
 454                 return shl_real(static_cast<double>(val));
 455 #endif
 456             }
 457
 458             // Adding constness to characters. Constness does not change layout
 459             template <class C, std::size_t N>
 460             BOOST_DEDUCED_TYPENAME boost::disable_if<boost::is_const<C>, bool>::type
 461             operator<<(boost::array<C, N> const& input) BOOST_NOEXCEPT {
 462                 BOOST_STATIC_ASSERT_MSG(
 463                     (sizeof(boost::array<const C, N>) == sizeof(boost::array<C, N>)),
 464                     "boost::array<C, N> and boost::array<const C, N> must have exactly the same layout."
 465                 );
 466                 return ((*this) << reinterpret_cast<boost::array<const C, N> const& >(input));
 467             }
 468
 469             template <std::size_t N>
 470             bool operator<<(boost::array<const CharT, N> const& input) BOOST_NOEXCEPT {
 471                 return shl_char_array_limited(input.data(), N);
 472             }
 473
 474             template <std::size_t N>
 475             bool operator<<(boost::array<const unsigned char, N> const& input) BOOST_NOEXCEPT {
 476                 return ((*this) << reinterpret_cast<boost::array<const char, N> const& >(input));
 477             }
 478
 479             template <std::size_t N>
 480             bool operator<<(boost::array<const signed char, N> const& input) BOOST_NOEXCEPT {
 481                 return ((*this) << reinterpret_cast<boost::array<const char, N> const& >(input));
 482             }
 483
 484 #ifndef BOOST_NO_CXX11_HDR_ARRAY
 485             // Making a Boost.Array from std::array
 486             template <class C, std::size_t N>
 487             bool operator<<(std::array<C, N> const& input) BOOST_NOEXCEPT {
 488                 BOOST_STATIC_ASSERT_MSG(
 489                     (sizeof(std::array<C, N>) == sizeof(boost::array<C, N>)),
 490                     "std::array and boost::array must have exactly the same layout. "
 491                     "Bug in implementation of std::array or boost::array."
 492                 );
 493                 return ((*this) << reinterpret_cast<boost::array<C, N> const& >(input));
 494             }
 495 #endif
 496             template <class InStreamable>
 497             bool operator<<(const InStreamable& input)  { return shl_input_streamable(input); }
 498         };
 499
 500
 501         template <class CharT, class Traits>
 502         class lexical_ostream_limited_src: boost::noncopyable {
 503             //`[start, finish)` is the range to output by `operator >>`
 504             const CharT*        start;
 505             const CharT* const  finish;
 506
 507         public:
 508             lexical_ostream_limited_src(const CharT* begin, const CharT* end) BOOST_NOEXCEPT
 509               : start(begin)
 510               , finish(end)
 511             {}
 512
 513 /************************************ HELPER FUNCTIONS FOR OPERATORS >> ( ... ) ********************************/
 514         private:
 515             template <typename Type>
 516             bool shr_unsigned(Type& output) {
 517                 if (start == finish) return false;
 518                 CharT const minus = lcast_char_constants<CharT>::minus;
 519                 CharT const plus = lcast_char_constants<CharT>::plus;
 520                 bool const has_minus = Traits::eq(minus, *start);
 521
 522                 /* We won`t use `start' any more, so no need in decrementing it after */
 523                 if (has_minus || Traits::eq(plus, *start)) {
 524                     ++start;
 525                 }
 526
 527                 bool const succeed = lcast_ret_unsigned<Traits, Type, CharT>(output, start, finish).convert();
 528
 529                 if (has_minus) {
 530                     output = static_cast<Type>(0u - output);
 531                 }
 532
 533                 return succeed;
 534             }
 535
 536             template <typename Type>
 537             bool shr_signed(Type& output) {
 538                 if (start == finish) return false;
 539                 CharT const minus = lcast_char_constants<CharT>::minus;
 540                 CharT const plus = lcast_char_constants<CharT>::plus;
 541                 typedef BOOST_DEDUCED_TYPENAME make_unsigned<Type>::type utype;
 542                 utype out_tmp = 0;
 543                 bool const has_minus = Traits::eq(minus, *start);
 544
 545                 /* We won`t use `start' any more, so no need in decrementing it after */
 546                 if (has_minus || Traits::eq(plus, *start)) {
 547                     ++start;
 548                 }
 549
 550                 bool succeed = lcast_ret_unsigned<Traits, utype, CharT>(out_tmp, start, finish).convert();
 551                 if (has_minus) {
 552                     utype const comp_val = (static_cast<utype>(1) << std::numeric_limits<Type>::digits);
 553                     succeed = succeed && out_tmp<=comp_val;
 554                     output = static_cast<Type>(0u - out_tmp);
 555                 } else {
 556                     utype const comp_val = static_cast<utype>((std::numeric_limits<Type>::max)());
 557                     succeed = succeed && out_tmp<=comp_val;
 558                     output = static_cast<Type>(out_tmp);
 559                 }
 560                 return succeed;
 561             }
 562
 563             template<typename InputStreamable>
 564             bool shr_using_base_class(InputStreamable& output)
 565             {
 566                 BOOST_STATIC_ASSERT_MSG(
 567                     (!boost::is_pointer<InputStreamable>::value),
 568                     "boost::lexical_cast can not convert to pointers"
 569                 );
 570
 571 #if defined(BOOST_NO_STRINGSTREAM) || defined(BOOST_NO_STD_LOCALE)
 572                 BOOST_STATIC_ASSERT_MSG((boost::is_same<char, CharT>::value),
 573                     "boost::lexical_cast can not convert, because your STL library does not "
 574                     "support such conversions. Try updating it."
 575                 );
 576 #endif
 577
 578 #if defined(BOOST_NO_STRINGSTREAM)
 579                 std::istrstream stream(start, static_cast<std::istrstream::streamsize>(finish - start));
 580 #else
 581                 typedef BOOST_DEDUCED_TYPENAME out_stream_helper_trait<CharT, Traits>::buffer_t buffer_t;
 582                 buffer_t buf;
 583                 // Usually `istream` and `basic_istream` do not modify
 584                 // content of buffer; `buffer_t` assures that this is true
 585                 buf.setbuf(const_cast<CharT*>(start), static_cast<typename buffer_t::streamsize>(finish - start));
 586 #if defined(BOOST_NO_STD_LOCALE)
 587                 std::istream stream(&buf);
 588 #else
 589                 std::basic_istream<CharT, Traits> stream(&buf);
 590 #endif // BOOST_NO_STD_LOCALE
 591 #endif // BOOST_NO_STRINGSTREAM
 592
 593 #ifndef BOOST_NO_EXCEPTIONS
 594                 stream.exceptions(std::ios::badbit);
 595                 try {
 596 #endif
 597                 stream.unsetf(std::ios::skipws);
 598                 lcast_set_precision(stream, static_cast<InputStreamable*>(0));
 599
 600                 return (stream >> output)
 601                     && (stream.get() == Traits::eof());
 602
 603 #ifndef BOOST_NO_EXCEPTIONS
 604                 } catch (const ::std::ios_base::failure& /*f*/) {
 605                     return false;
 606                 }
 607 #endif
 608             }
 609
 610             template<class T>
 611             inline bool shr_xchar(T& output) BOOST_NOEXCEPT {
 612                 BOOST_STATIC_ASSERT_MSG(( sizeof(CharT) == sizeof(T) ),
 613                     "boost::lexical_cast does not support narrowing of character types."
 614                     "Use boost::locale instead" );
 615                 bool const ok = (finish - start == 1);
 616                 if (ok) {
 617                     CharT out;
 618                     Traits::assign(out, *start);
 619                     output = static_cast<T>(out);
 620                 }
 621                 return ok;
 622             }
 623
 624             template <std::size_t N, class ArrayT>
 625             bool shr_std_array(ArrayT& output) BOOST_NOEXCEPT {
 626                 using namespace std;
 627                 const std::size_t size = static_cast<std::size_t>(finish - start);
 628                 if (size > N - 1) { // `-1` because we need to store \0 at the end
 629                     return false;
 630                 }
 631
 632                 memcpy(&output[0], start, size * sizeof(CharT));
 633                 output[size] = Traits::to_char_type(0);
 634                 return true;
 635             }
 636
 637 /************************************ OPERATORS >> ( ... ) ********************************/
 638         public:
 639             bool operator>>(unsigned short& output)             { return shr_unsigned(output); }
 640             bool operator>>(unsigned int& output)               { return shr_unsigned(output); }
 641             bool operator>>(unsigned long int& output)          { return shr_unsigned(output); }
 642             bool operator>>(short& output)                      { return shr_signed(output); }
 643             bool operator>>(int& output)                        { return shr_signed(output); }
 644             bool operator>>(long int& output)                   { return shr_signed(output); }
 645 #if defined(BOOST_HAS_LONG_LONG)
 646             bool operator>>(boost::ulong_long_type& output)     { return shr_unsigned(output); }
 647             bool operator>>(boost::long_long_type& output)      { return shr_signed(output); }
 648 #elif defined(BOOST_HAS_MS_INT64)
 649             bool operator>>(unsigned __int64& output)           { return shr_unsigned(output); }
 650             bool operator>>(__int64& output)                    { return shr_signed(output); }
 651 #endif
 652
 653 #ifdef BOOST_HAS_INT128
 654             bool operator>>(boost::uint128_type& output)        { return shr_unsigned(output); }
 655             bool operator>>(boost::int128_type& output)         { return shr_signed(output); }
 656 #endif
 657
 658             bool operator>>(char& output)                       { return shr_xchar(output); }
 659             bool operator>>(unsigned char& output)              { return shr_xchar(output); }
 660             bool operator>>(signed char& output)                { return shr_xchar(output); }
 661 #if !defined(BOOST_LCAST_NO_WCHAR_T) && !defined(BOOST_NO_INTRINSIC_WCHAR_T)
 662             bool operator>>(wchar_t& output)                    { return shr_xchar(output); }
 663 #endif
 664 #if !defined(BOOST_NO_CXX11_CHAR16_T) && !defined(BOOST_NO_CXX11_UNICODE_LITERALS)
 665             bool operator>>(char16_t& output)                   { return shr_xchar(output); }
 666 #endif
 667 #if !defined(BOOST_NO_CXX11_CHAR32_T) && !defined(BOOST_NO_CXX11_UNICODE_LITERALS)
 668             bool operator>>(char32_t& output)                   { return shr_xchar(output); }
 669 #endif
 670             template<class Alloc>
 671             bool operator>>(std::basic_string<CharT,Traits,Alloc>& str) {
 672                 str.assign(start, finish); return true;
 673             }
 674
 675             template<class Alloc>
 676             bool operator>>(boost::container::basic_string<CharT,Traits,Alloc>& str) {
 677                 str.assign(start, finish); return true;
 678             }
 679
 680             template <std::size_t N>
 681             bool operator>>(boost::array<CharT, N>& output) BOOST_NOEXCEPT {
 682                 return shr_std_array<N>(output);
 683             }
 684
 685             template <std::size_t N>
 686             bool operator>>(boost::array<unsigned char, N>& output) BOOST_NOEXCEPT {
 687                 return ((*this) >> reinterpret_cast<boost::array<char, N>& >(output));
 688             }
 689
 690             template <std::size_t N>
 691             bool operator>>(boost::array<signed char, N>& output) BOOST_NOEXCEPT {
 692                 return ((*this) >> reinterpret_cast<boost::array<char, N>& >(output));
 693             }
 694
 695 #ifndef BOOST_NO_CXX11_HDR_ARRAY
 696             template <class C, std::size_t N>
 697             bool operator>>(std::array<C, N>& output) BOOST_NOEXCEPT {
 698                 BOOST_STATIC_ASSERT_MSG(
 699                     (sizeof(std::array<C, N>) == sizeof(boost::array<C, N>)),
 700                     "std::array<C, N> and boost::array<C, N> must have exactly the same layout."
 701                 );
 702                 return ((*this) >> reinterpret_cast<boost::array<C, N>& >(output));
 703             }
 704 #endif
 705
 706             bool operator>>(bool& output) BOOST_NOEXCEPT {
 707                 output = false; // Suppress warning about uninitalized variable
 708
 709                 if (start == finish) return false;
 710                 CharT const zero = lcast_char_constants<CharT>::zero;
 711                 CharT const plus = lcast_char_constants<CharT>::plus;
 712                 CharT const minus = lcast_char_constants<CharT>::minus;
 713
 714                 const CharT* const dec_finish = finish - 1;
 715                 output = Traits::eq(*dec_finish, zero + 1);
 716                 if (!output && !Traits::eq(*dec_finish, zero)) {
 717                     return false; // Does not ends on '0' or '1'
 718                 }
 719
 720                 if (start == dec_finish) return true;
 721
 722                 // We may have sign at the beginning
 723                 if (Traits::eq(plus, *start) || (Traits::eq(minus, *start) && !output)) {
 724                     ++ start;
 725                 }
 726
 727                 // Skipping zeros
 728                 while (start != dec_finish) {
 729                     if (!Traits::eq(zero, *start)) {
 730                         return false; // Not a zero => error
 731                     }
 732
 733                     ++ start;
 734                 }
 735
 736                 return true;
 737             }
 738
 739         private:
 740             // Not optimised converter
 741             template <class T>
 742             bool float_types_converter_internal(T& output) {
 743                 if (parse_inf_nan(start, finish, output)) return true;
 744                 bool const return_value = shr_using_base_class(output);
 745
 746                 /* Some compilers and libraries successfully
 747                  * parse 'inf', 'INFINITY', '1.0E', '1.0E-'...
 748                  * We are trying to provide a unified behaviour,
 749                  * so we just forbid such conversions (as some
 750                  * of the most popular compilers/libraries do)
 751                  * */
 752                 CharT const minus = lcast_char_constants<CharT>::minus;
 753                 CharT const plus = lcast_char_constants<CharT>::plus;
 754                 CharT const capital_e = lcast_char_constants<CharT>::capital_e;
 755                 CharT const lowercase_e = lcast_char_constants<CharT>::lowercase_e;
 756                 if ( return_value &&
 757                      (
 758                         Traits::eq(*(finish-1), lowercase_e)                   // 1.0e
 759                         || Traits::eq(*(finish-1), capital_e)                  // 1.0E
 760                         || Traits::eq(*(finish-1), minus)                      // 1.0e- or 1.0E-
 761                         || Traits::eq(*(finish-1), plus)                       // 1.0e+ or 1.0E+
 762                      )
 763                 ) return false;
 764
 765                 return return_value;
 766             }
 767
 768         public:
 769             bool operator>>(float& output) { return float_types_converter_internal(output); }
 770             bool operator>>(double& output) { return float_types_converter_internal(output); }
 771             bool operator>>(long double& output) { return float_types_converter_internal(output); }
 772
 773             // Generic istream-based algorithm.
 774             // lcast_streambuf_for_target<InputStreamable>::value is true.
 775             template <typename InputStreamable>
 776             bool operator>>(InputStreamable& output) {
 777                 return shr_using_base_class(output);
 778             }
 779         };
 780     }
 781 } // namespace boost
 782
 783 #undef BOOST_LCAST_NO_WCHAR_T
 784
 785 #endif // BOOST_LEXICAL_CAST_DETAIL_CONVERTER_LEXICAL_HPP
 786