Squashed 'third_party/boostorg/lexical_cast/' content from commit 5bfe667

Change-Id: I518d0a0b83082059176813a98b80ad92892ac745
git-subtree-dir: third_party/boostorg/lexical_cast
git-subtree-split: 5bfe6672d467ebd8de5d911c07b2a931b43156de
diff --git a/include/boost/detail/basic_pointerbuf.hpp b/include/boost/detail/basic_pointerbuf.hpp
new file mode 100644
index 0000000..85618f9
--- /dev/null
+++ b/include/boost/detail/basic_pointerbuf.hpp
@@ -0,0 +1,139 @@
+//-----------------------------------------------------------------------------
+// boost detail/templated_streams.hpp header file
+// See http://www.boost.org for updates, documentation, and revision history.
+//-----------------------------------------------------------------------------
+//
+// Copyright (c) 2013 John Maddock, Antony Polukhin
+// 
+//
+// Distributed under the Boost Software License, Version 1.0. (See
+// accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_DETAIL_BASIC_POINTERBUF_HPP
+#define BOOST_DETAIL_BASIC_POINTERBUF_HPP
+
+// MS compatible compilers support #pragma once
+#if defined(_MSC_VER)
+# pragma once
+#endif
+
+#include "boost/config.hpp"
+#include <streambuf>
+
+namespace boost { namespace detail {
+
+//
+// class basic_pointerbuf:
+// acts as a stream buffer which wraps around a pair of pointers:
+//
+template <class charT, class BufferT >
+class basic_pointerbuf : public BufferT {
+protected:
+   typedef BufferT base_type;
+   typedef basic_pointerbuf<charT, BufferT> this_type;
+   typedef typename base_type::int_type int_type;
+   typedef typename base_type::char_type char_type;
+   typedef typename base_type::pos_type pos_type;
+   typedef ::std::streamsize streamsize;
+   typedef typename base_type::off_type off_type;
+
+public:
+   basic_pointerbuf() : base_type() { this_type::setbuf(0, 0); }
+   const charT* getnext() { return this->gptr(); }
+
+#ifndef BOOST_NO_USING_TEMPLATE
+    using base_type::pptr;
+    using base_type::pbase;
+#else
+    charT* pptr() const { return base_type::pptr(); }
+    charT* pbase() const { return base_type::pbase(); }
+#endif
+
+protected:
+   // VC mistakenly assumes that `setbuf` and other functions are not referenced.
+   // Marking those functions with `inline` suppresses the warnings.
+   // There must be no harm from marking virtual functions as inline: inline virtual
+   // call can be inlined ONLY when the compiler knows the "exact class".
+   inline base_type* setbuf(char_type* s, streamsize n);
+   inline typename this_type::pos_type seekpos(pos_type sp, ::std::ios_base::openmode which);
+   inline typename this_type::pos_type seekoff(off_type off, ::std::ios_base::seekdir way, ::std::ios_base::openmode which);
+
+private:
+   basic_pointerbuf& operator=(const basic_pointerbuf&);
+   basic_pointerbuf(const basic_pointerbuf&);
+};
+
+template<class charT, class BufferT>
+BufferT*
+basic_pointerbuf<charT, BufferT>::setbuf(char_type* s, streamsize n)
+{
+   this->setg(s, s, s + n);
+   return this;
+}
+
+template<class charT, class BufferT>
+typename basic_pointerbuf<charT, BufferT>::pos_type
+basic_pointerbuf<charT, BufferT>::seekoff(off_type off, ::std::ios_base::seekdir way, ::std::ios_base::openmode which)
+{
+   typedef typename boost::int_t<sizeof(way) * CHAR_BIT>::least cast_type;
+
+   if(which & ::std::ios_base::out)
+      return pos_type(off_type(-1));
+   std::ptrdiff_t size = this->egptr() - this->eback();
+   std::ptrdiff_t pos = this->gptr() - this->eback();
+   charT* g = this->eback();
+   switch(static_cast<cast_type>(way))
+   {
+   case ::std::ios_base::beg:
+      if((off < 0) || (off > size))
+         return pos_type(off_type(-1));
+      else
+         this->setg(g, g + off, g + size);
+      break;
+   case ::std::ios_base::end:
+      if((off < 0) || (off > size))
+         return pos_type(off_type(-1));
+      else
+         this->setg(g, g + size - off, g + size);
+      break;
+   case ::std::ios_base::cur:
+   {
+      std::ptrdiff_t newpos = static_cast<std::ptrdiff_t>(pos + off);
+      if((newpos < 0) || (newpos > size))
+         return pos_type(off_type(-1));
+      else
+         this->setg(g, g + newpos, g + size);
+      break;
+   }
+   default: ;
+   }
+#ifdef BOOST_MSVC
+#pragma warning(push)
+#pragma warning(disable:4244)
+#endif
+   return static_cast<pos_type>(this->gptr() - this->eback());
+#ifdef BOOST_MSVC
+#pragma warning(pop)
+#endif
+}
+
+template<class charT, class BufferT>
+typename basic_pointerbuf<charT, BufferT>::pos_type
+basic_pointerbuf<charT, BufferT>::seekpos(pos_type sp, ::std::ios_base::openmode which)
+{
+   if(which & ::std::ios_base::out)
+      return pos_type(off_type(-1));
+   off_type size = static_cast<off_type>(this->egptr() - this->eback());
+   charT* g = this->eback();
+   if(off_type(sp) <= size)
+   {
+      this->setg(g, g + off_type(sp), g + size);
+   }
+   return pos_type(off_type(-1));
+}
+
+}} // namespace boost::detail
+
+#endif // BOOST_DETAIL_BASIC_POINTERBUF_HPP
+
diff --git a/include/boost/detail/lcast_precision.hpp b/include/boost/detail/lcast_precision.hpp
new file mode 100644
index 0000000..2be88fd
--- /dev/null
+++ b/include/boost/detail/lcast_precision.hpp
@@ -0,0 +1,185 @@
+// Copyright Alexander Nasonov & Paul A. Bristow 2006.
+
+// Use, modification and distribution are subject to the
+// Boost Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt
+// or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_DETAIL_LCAST_PRECISION_HPP_INCLUDED
+#define BOOST_DETAIL_LCAST_PRECISION_HPP_INCLUDED
+
+#include <climits>
+#include <ios>
+#include <limits>
+
+#include <boost/config.hpp>
+#include <boost/integer_traits.hpp>
+
+#ifndef BOOST_NO_IS_ABSTRACT
+// Fix for SF:1358600 - lexical_cast & pure virtual functions & VC 8 STL
+#include <boost/mpl/if.hpp>
+#include <boost/type_traits/is_abstract.hpp>
+#endif
+
+#if defined(BOOST_NO_LIMITS_COMPILE_TIME_CONSTANTS) || \
+  (defined(BOOST_MSVC) && (BOOST_MSVC<1310))
+
+#define BOOST_LCAST_NO_COMPILE_TIME_PRECISION
+#endif
+
+#ifdef BOOST_LCAST_NO_COMPILE_TIME_PRECISION
+#include <boost/assert.hpp>
+#else
+#include <boost/static_assert.hpp>
+#endif
+
+namespace boost { namespace detail {
+
+class lcast_abstract_stub {};
+
+#ifndef BOOST_LCAST_NO_COMPILE_TIME_PRECISION
+// Calculate an argument to pass to std::ios_base::precision from
+// lexical_cast. See alternative implementation for broken standard
+// libraries in lcast_get_precision below. Keep them in sync, please.
+template<class T>
+struct lcast_precision
+{
+#ifdef BOOST_NO_IS_ABSTRACT
+    typedef std::numeric_limits<T> limits; // No fix for SF:1358600.
+#else
+    typedef BOOST_DEDUCED_TYPENAME boost::mpl::if_<
+        boost::is_abstract<T>
+      , std::numeric_limits<lcast_abstract_stub>
+      , std::numeric_limits<T>
+      >::type limits;
+#endif
+
+    BOOST_STATIC_CONSTANT(bool, use_default_precision =
+            !limits::is_specialized || limits::is_exact
+        );
+
+    BOOST_STATIC_CONSTANT(bool, is_specialized_bin =
+            !use_default_precision &&
+            limits::radix == 2 && limits::digits > 0
+        );
+
+    BOOST_STATIC_CONSTANT(bool, is_specialized_dec =
+            !use_default_precision &&
+            limits::radix == 10 && limits::digits10 > 0
+        );
+
+    BOOST_STATIC_CONSTANT(std::streamsize, streamsize_max =
+            boost::integer_traits<std::streamsize>::const_max
+        );
+
+    BOOST_STATIC_CONSTANT(unsigned int, precision_dec = limits::digits10 + 1U);
+
+    BOOST_STATIC_ASSERT(!is_specialized_dec ||
+            precision_dec <= streamsize_max + 0UL
+        );
+
+    BOOST_STATIC_CONSTANT(unsigned long, precision_bin =
+            2UL + limits::digits * 30103UL / 100000UL
+        );
+
+    BOOST_STATIC_ASSERT(!is_specialized_bin ||
+            (limits::digits + 0UL < ULONG_MAX / 30103UL &&
+            precision_bin > limits::digits10 + 0UL &&
+            precision_bin <= streamsize_max + 0UL)
+        );
+
+    BOOST_STATIC_CONSTANT(std::streamsize, value =
+            is_specialized_bin ? precision_bin
+                               : is_specialized_dec ? precision_dec : 6
+        );
+};
+#endif
+
+template<class T>
+inline std::streamsize lcast_get_precision(T* = 0)
+{
+#ifndef BOOST_LCAST_NO_COMPILE_TIME_PRECISION
+    return lcast_precision<T>::value;
+#else // Follow lcast_precision algorithm at run-time:
+
+#ifdef BOOST_NO_IS_ABSTRACT
+    typedef std::numeric_limits<T> limits; // No fix for SF:1358600.
+#else
+    typedef BOOST_DEDUCED_TYPENAME boost::mpl::if_<
+        boost::is_abstract<T>
+      , std::numeric_limits<lcast_abstract_stub>
+      , std::numeric_limits<T>
+      >::type limits;
+#endif
+
+    bool const use_default_precision =
+        !limits::is_specialized || limits::is_exact;
+
+    if(!use_default_precision)
+    { // Includes all built-in floating-point types, float, double ...
+      // and UDT types for which digits (significand bits) is defined (not zero)
+
+        bool const is_specialized_bin =
+            limits::radix == 2 && limits::digits > 0;
+        bool const is_specialized_dec =
+            limits::radix == 10 && limits::digits10 > 0;
+        std::streamsize const streamsize_max =
+            (boost::integer_traits<std::streamsize>::max)();
+        (void)streamsize_max;
+
+        if(is_specialized_bin)
+        { // Floating-point types with
+          // limits::digits defined by the specialization.
+
+            unsigned long const digits = limits::digits;
+            unsigned long const precision = 2UL + digits * 30103UL / 100000UL;
+            // unsigned long is selected because it is at least 32-bits
+            // and thus ULONG_MAX / 30103UL is big enough for all types.
+            BOOST_ASSERT(
+                    digits < ULONG_MAX / 30103UL &&
+                    precision > limits::digits10 + 0UL &&
+                    precision <= streamsize_max + 0UL
+                );
+            return precision;
+        }
+        else if(is_specialized_dec)
+        {   // Decimal Floating-point type, most likely a User Defined Type
+            // rather than a real floating-point hardware type.
+            unsigned int const precision = limits::digits10 + 1U;
+            BOOST_ASSERT(precision <= streamsize_max + 0UL);
+            return precision;
+        }
+    }
+
+    // Integral type (for which precision has no effect)
+    // or type T for which limits is NOT specialized,
+    // so assume stream precision remains the default 6 decimal digits.
+    // Warning: if your User-defined Floating-point type T is NOT specialized,
+    // then you may lose accuracy by only using 6 decimal digits.
+    // To avoid this, you need to specialize T with either
+    // radix == 2 and digits == the number of significand bits,
+    // OR
+    // radix = 10 and digits10 == the number of decimal digits.
+
+    return 6;
+#endif
+}
+
+template<class T>
+inline void lcast_set_precision(std::ios_base& stream, T*)
+{
+    stream.precision(lcast_get_precision<T>());
+}
+
+template<class Source, class Target>
+inline void lcast_set_precision(std::ios_base& stream, Source*, Target*)
+{
+    std::streamsize const s = lcast_get_precision(static_cast<Source*>(0));
+    std::streamsize const t = lcast_get_precision(static_cast<Target*>(0));
+    stream.precision(s > t ? s : t);
+}
+
+}}
+
+#endif //  BOOST_DETAIL_LCAST_PRECISION_HPP_INCLUDED
+