From 115ad05af522ac1df1ddf97c41d2ec0d65830f41 Mon Sep 17 00:00:00 2001
From: Alexander Nasonov <alnsn@yandex.ru>
Date: Wed, 11 Oct 2006 19:43:54 +0000
Subject: [PATCH] Set precision correctly for builtin and UDT floating types.

[SVN r35562]
---
 include/boost/detail/lcast_precision.hpp | 10 +++++-----
 include/boost/lexical_cast.hpp           | 24 +++---------------------
 2 files changed, 8 insertions(+), 26 deletions(-)

diff --git a/include/boost/detail/lcast_precision.hpp b/include/boost/detail/lcast_precision.hpp
index 49345d5..085c569 100644
--- a/include/boost/detail/lcast_precision.hpp
+++ b/include/boost/detail/lcast_precision.hpp
@@ -5,8 +5,8 @@
 // (See accompanying file LICENSE_1_0.txt
 // or copy at http://www.boost.org/LICENSE_1_0.txt)
 
-#ifndef BOOST_DETAIL_LCAST_SET_PRECISION_HPP_INCLUDED
-#define BOOST_DETAIL_LCAST_SET_PRECISION_HPP_INCLUDED
+#ifndef BOOST_DETAIL_LCAST_PRECISION_HPP_INCLUDED
+#define BOOST_DETAIL_LCAST_PRECISION_HPP_INCLUDED
 
 #include <climits>
 #include <ios>
@@ -28,7 +28,7 @@ namespace boost { namespace detail {
 
 #ifdef _MSC_VER
 #pragma warning (push)
-// conditional expression is constant (stream precision)
+// conditional expression is constant
 #pragma warning (disable : 4127)
 #endif
 
@@ -85,7 +85,7 @@ inline std::streamsize lcast_get_precision()
     // radix = 10 and digits10 == the number of decimal digits.
 
     return 6;
-} // template<class T> bool lcast_set_precision(std::ios_base& stream)
+}
 
 template<class T>
 inline void lcast_set_precision(std::ios_base& stream)
@@ -109,5 +109,5 @@ inline void lcast_set_precision(std::ios_base& stream)
 
 #undef BOOST_DETAIL_LCAST_ASSERT
 
-#endif //  BOOST_DETAIL_LCAST_SET_PRECISION_HPP_INCLUDED
+#endif //  BOOST_DETAIL_LCAST_PRECISION_HPP_INCLUDED
 
diff --git a/include/boost/lexical_cast.hpp b/include/boost/lexical_cast.hpp
index e8ac499..8b88bad 100644
--- a/include/boost/lexical_cast.hpp
+++ b/include/boost/lexical_cast.hpp
@@ -27,6 +27,7 @@
 #include <boost/type_traits/is_pointer.hpp>
 #include <boost/call_traits.hpp>
 #include <boost/static_assert.hpp>
+#include <boost/detail/lcast_precision.hpp>
 
 #ifdef BOOST_NO_STRINGSTREAM
 #include <strstream>
@@ -458,25 +459,7 @@ namespace boost
             lexical_stream(char_type* = 0, char_type* = 0)
             {
                 stream.unsetf(std::ios::skipws);
-
-#if (defined _MSC_VER)
-# pragma warning( push )
-  // conditional expression is constant
-# pragma warning( disable : 4127 )
-#endif
-
-                typedef std::numeric_limits<Target> t;
-                typedef std::numeric_limits<Source> s;
-
-                if(t::is_specialized)
-                    stream.precision(1 + t::digits10);
-                else if(s::is_specialized)
-                    stream.precision(1 + s::digits10);
-
-#if (defined _MSC_VER)
-# pragma warning( pop )
-#endif
-
+                lcast_set_precision<Source, Target>(stream);
             }
             ~lexical_stream()
             {
@@ -626,8 +609,7 @@ namespace boost
 
                 typedef std::numeric_limits<InputStreamable> limits;
 
-                if(limits::is_specialized)
-                    stream.precision(limits::digits10 + 1);
+                lcast_set_precision<InputStreamable>(stream);
 #if (defined _MSC_VER)
 # pragma warning( pop )
 #endif