[Boost-commit] svn:boost r86499 - trunk/boost/archive

Subject: [Boost-commit] svn:boost r86499 - trunk/boost/archive
From: ramey_at_[hidden]
Date: 2013-10-28 11:34:59

Author: ramey
Date: 2013-10-28 11:34:58 EDT (Mon, 28 Oct 2013)
New Revision: 86499
URL: http://svn.boost.org/trac/boost/changeset/86499

Log:
corrected # digits

Text files modified: 
   trunk/boost/archive/basic_text_oprimitive.hpp |     8 +++++---                                
   1 files changed, 5 insertions(+), 3 deletions(-)

Modified: trunk/boost/archive/basic_text_oprimitive.hpp
==============================================================================
--- trunk/boost/archive/basic_text_oprimitive.hpp	Mon Oct 28 06:34:51 2013	(r86498)
+++ trunk/boost/archive/basic_text_oprimitive.hpp	2013-10-28 11:34:58 EDT (Mon, 28 Oct 2013)	(r86499)
@@ -160,9 +160,11 @@
         // http://www2.open-std.org/JTC1/SC22/WG21/docs/papers/2005/n1822.pdf
         // which is derived from Kahan's paper:
         // http://http.cs.berkley.edu/~wkahan/ieee754status/ieee754.ps
-        const unsigned int digits = (std::numeric_limits<float>::digits * 3010) / 10000;
-        os << std::setprecision(digits);
-        os << t;
+        // const unsigned int digits = (std::numeric_limits<T>::digits * 3010) / 10000;
+        // note: I've commented out the above because I didn't get good results.  e.g.
+        // in one case I got a difference of 19 units.
+        const unsigned int digits = std::numeric_limits<T>::digits10 + 2;
+        os << std::setprecision(digits) << std::scientific << t;
     }
 
     template<class T>