stdcpp/src/num_put_float.cpp
changeset 0 e4d67989cc36
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/stdcpp/src/num_put_float.cpp	Tue Feb 02 02:01:42 2010 +0200
@@ -0,0 +1,764 @@
+/*
+ * © Portions copyright (c) 2006-2007 Nokia Corporation.  All rights reserved.
+ *
+ * Copyright (c) 1999
+ * Silicon Graphics Computer Systems, Inc.
+ *
+ * Copyright (c) 1999 
+ * Boris Fomitchev
+ *
+ * This material is provided "as is", with absolutely no warranty expressed
+ * or implied. Any use is at your own risk.
+ *
+ * Permission to use or copy this software for any purpose is hereby granted 
+ * without fee, provided the above notices are retained on all copies.
+ * Permission to modify the code and to distribute modified code is granted,
+ * provided the above notices are retained, and a notice that the code was
+ * modified is included with the above copyright notice.
+ *
+ */
+
+# include "stlport_prefix.h"
+
+# ifdef __DECCXX
+#define NDIG 400
+# else
+#define NDIG 82
+# endif
+
+# ifdef _STLP_NO_LONG_DOUBLE
+#  define MAXECVT 17
+#  define MAXFCVT 18
+typedef double max_double_type;
+# else
+#  define MAXECVT 35
+#  define MAXFCVT 36
+typedef long double max_double_type;
+# endif
+
+#define MAXFSIG MAXECVT
+#define MAXESIZ 5
+
+#define todigit(x) ((x)+'0')
+
+# include <stl/_config.h>
+
+# ifdef _STLP_UNIX
+
+# if defined (__sun) 
+#  include <floatingpoint.h>
+# endif
+
+//# if !(defined(_STLP_USE_GLIBC) || defined(__FreeBSD__) || defined(__NetBSD__) || defined (_AIX) || defined(__MVS__) || defined (__OS400__) || defined (__QNXNTO__) || defined (__APPLE__) || defined (__DJGPP))
+# if defined (__sun) || defined (__digital__) || defined (__sgi) || defined (_STLP_SCO_OPENSERVER) || defined (__NCR_SVR)
+// DEC, SGI & Solaris need this
+#  include <values.h>
+#  include <nan.h>
+# endif
+
+# if defined (__QNXNTO__) || ( defined(__GNUC__) && defined(__APPLE__) )
+#  define USE_SPRINTF_INSTEAD
+# endif
+
+#  if defined( _AIX ) // JFA 3-Aug-2000
+#    include <math.h>
+#    include <float.h>
+#  endif
+
+# endif
+
+# include <cstdlib>
+
+//#if defined(_CRAY)
+//# include <stdlib.h>
+//#endif
+
+#if defined (_MSC_VER) || defined (__MINGW32__) || defined (__BORLANDC__) || defined (__DJGPP)  || defined (_STLP_SCO_OPENSERVER) || defined (__NCR_SVR)
+# include <float.h>
+#endif
+
+#if defined(__MRC__) || defined(__SC__)	|| defined(_CRAY)	//*TY 02/24/2000 - added support for MPW
+# include <fp.h>
+#endif
+
+#include <cmath>
+
+#if defined( __MSL__ )
+# include <cstdlib>	// for atoi
+# include <cstdio>	// for snprintf
+# include <algorithm>
+# include <cassert>
+#endif
+
+#if defined (__ISCPP__)
+# include <cfloat>
+#endif
+
+
+# include "num_put.h"
+# include <algorithm>
+
+
+#if defined(__hpux) && !defined(_INCLUDE_HPUX_SOURCE)
+     extern "C" double erf(double);
+     extern "C" double erfc(double);
+     extern "C" double gamma(double);                             /* obsolescent */
+     extern "C" double hypot(double, double);
+     extern "C" int    isnan(double);
+     extern "C" double j0(double);
+     extern "C" double j1(double);
+     extern "C" double jn(int, double);
+     extern "C" double lgamma(double);
+     extern "C" double y0(double);
+     extern "C" double y1(double);
+     extern "C" double yn(int, double);
+
+#  define HUGE_VALF     _SINFINITY
+#  define INFINITY      _SINFINITY
+#  define NAN           _SQNAN
+
+#  define isnan(x)              _ISNAN(x)
+#  define isinf(x)              _ISINF(x)
+#  define signbit(x)            _SIGNBIT(x)
+#  define isfinite(x)           _ISFINITE(x)
+#  define isnormal(x)           _ISNORMAL(x)
+#  define fpclassify(x)         _FPCLASSIFY(x)
+#  define isunordered(x,y)      _ISUNORDERED(x,y)
+#  define isgreater(x,y)        _ISGREATER(x,y)
+#  define isgreaterequal(x,y)   _ISGREATEREQUAL(x,y)
+#  define isless(x,y)           _ISLESS(x,y)
+#  define islessequal(x,y)      _ISLESSEQUAL(x,y)
+#  define islessgreater(x,y)    _ISLESSGREATER(x,y)
+
+#  define FP_NORMAL     0
+#  define FP_ZERO       1
+#  define FP_INFINITE   2
+#  define FP_SUBNORMAL  3
+#  define FP_NAN        4
+
+#  define DECIMAL_DIG   17
+
+#  define _IS64(x) (sizeof(x)==sizeof(double))
+#  define _IS32(x) (sizeof(x)==sizeof(float))
+
+extern "C" {
+     extern double copysign(double, double);
+     extern const float _SINFINITY;
+     extern const float _SQNAN;
+#    ifdef _PA_RISC
+#      define _ISNAN(x)          (_IS32(x)?_Isnanf(x):(isnan)(x))
+#      define _ISINF(x)          (_IS32(x)?_Isinff(x):_Isinf(x))
+#      define _SIGNBIT(x)        (_IS32(x)?_Signbitf(x):_Signbit(x))
+#      define _ISFINITE(x)       (_IS32(x)?_Isfinitef(x):_Isfinite(x))
+#      define _ISNORMAL(x)       (_IS32(x)?_Isnormalf(x):_Isnormal(x))
+#      define _FPCLASSIFY(x)     (_IS32(x)?_Fpclassifyf(x)>>1:_Fpclassify(x)>>1)
+#      define _ISUNORDERED(x,y)  (_IS32(x)&&_IS32(y)?_Isunorderedf(x,y):_Isunordered(x,y))
+       extern int _Signbit(double);
+       extern int _Signbitf(float);
+       extern int _Isnanf(float);
+       extern int _Isfinite(double);
+       extern int _Isfinitef(float);
+       extern int _Isinf(double);
+       extern int _Isinff(float);
+       extern int _Isnormal(double);
+       extern int _Isnormalf(float);
+       extern int _Isunordered(double, double);
+       extern int _Isunorderedf(float, float);
+       extern int _Fpclassify(double);
+       extern int _Fpclassifyf(float);
+#    else
+#      include "math_ia64_internal.h"
+#      define _FPCLASSIFY(x)     (_IS32(x)?_Fpclassf(x):_Fpclass(x))
+       extern int _Fpclass(double);
+       extern int _Fpclassf(float);
+#    endif
+}
+
+#ifndef _INCLUDE_XOPEN_SOURCE_EXTENDED
+extern "C" char *fcvt(double, int, int *, int *);
+extern "C" char *ecvt(double, int, int *, int *);
+#endif
+#ifndef _INCLUDE_HPUX_SOURCE
+#  ifndef _LONG_DOUBLE
+#    define _LONG_DOUBLE
+     typedef struct {
+       uint32_t word1, word2, word3, word4;
+     } long_double;
+#  endif /* _LONG_DOUBLE */
+extern "C" char *_ldecvt(long_double, int, int *, int *);
+extern "C" char *_ldfcvt(long_double, int, int *, int *);
+
+#endif
+
+#endif /* __hpux */
+
+_STLP_BEGIN_NAMESPACE
+
+#if defined (__MWERKS__) || defined(__BEOS__)
+#  define USE_SPRINTF_INSTEAD
+#endif
+
+# if defined (_AIX)
+// Some OS'es only provide non-reentrant primitives, so we have to use additional synchronization here
+# ifdef _REENTRANT
+static _STLP_STATIC_MUTEX __put_float_mutex _STLP_MUTEX_INITIALIZER;
+# define LOCK_CVT _STLP_auto_lock lock(__put_float_mutex);
+# define RETURN_CVT(ecvt, x, n, pt, sign, buf) strcpy(buf, ecvt(x, n, pt, sign)); return buf;
+# else
+# define LOCK_CVT
+# define RETURN_CVT(ecvt, x, n, pt, sign, buf) return ecvt(x, n, pt, sign);
+# endif
+# endif
+
+// Tests for infinity and NaN differ on different OSs.  We encapsulate
+// these differences here.
+
+#ifdef USE_SPRINTF_INSTEAD
+
+#elif defined (__hpux) || defined (__DJGPP) || ( defined(_STLP_USE_GLIBC) && ! defined (__MSL__) )
+#  if defined (isfinite) 
+inline bool _Stl_is_nan_or_inf(double x) { return !isfinite(x); }
+#  else
+inline bool _Stl_is_nan_or_inf(double x) { return !finite(x); }
+#  endif
+inline bool _Stl_is_neg_nan(double x)    { return isnan(x) && ( copysign(1., x) < 0 ); }
+inline bool _Stl_is_inf(double x)        { return isinf(x); }
+// inline bool _Stl_is_neg_inf(double x)    { return isinf(x) < 0; }  
+inline bool _Stl_is_neg_inf(double x)    { return isinf(x) && x < 0; }
+#elif defined(__unix) && !defined(__FreeBSD__)  && !defined(__NetBSD__) \
+      && !defined(__APPLE__)  && !defined(__DJGPP) && !defined(__osf__) \
+      && !defined(_CRAY)
+inline bool _Stl_is_nan_or_inf(double x) { return IsNANorINF(x); }
+inline bool _Stl_is_inf(double x)        { return IsNANorINF(x) && IsINF(x); }
+inline bool _Stl_is_neg_inf(double x)    { return (IsINF(x)) && (x < 0.0); }
+inline bool _Stl_is_neg_nan(double x)    { return IsNegNAN(x); }
+# elif defined (__BORLANDC__) && ( __BORLANDC__ < 0x540 )
+inline bool _Stl_is_nan_or_inf(double x) {  return !_finite(x); }
+inline bool _Stl_is_inf(double x)        {  return _Stl_is_nan_or_inf(x) && ! _isnan(x);}
+inline bool _Stl_is_neg_inf(double x)    {  return _Stl_is_inf(x) && x < 0 ; }
+inline bool _Stl_is_neg_nan(double x)    { return _isnan(x) && x < 0 ; } 
+#elif defined (_MSC_VER) || (defined (__MINGW32__) && !defined (__SYMBIAN32__)) || defined (__BORLANDC__) 
+inline bool _Stl_is_nan_or_inf(double x) { return !_finite(x); }
+inline bool _Stl_is_inf(double x)        { 
+  int fclass = _fpclass(x); 
+  return fclass == _FPCLASS_NINF || fclass == _FPCLASS_PINF; 
+}
+inline bool _Stl_is_neg_inf(double x)    { return _fpclass(x) == _FPCLASS_NINF; }
+inline bool _Stl_is_neg_nan(double x)    { return _isnan(x) && _copysign(1., x) < 0 ; } 
+#elif defined(__MRC__) || defined(__SC__)		//*TY 02/24/2000 - added support for MPW
+bool _Stl_is_nan_or_inf(double x) { return isnan(x) || !isfinite(x); }
+bool _Stl_is_inf(double x)        { return !isfinite(x); }
+bool _Stl_is_neg_inf(double x)    { return !isfinite(x) && signbit(x); }
+bool _Stl_is_neg_nan(double x)    { return isnan(x) && signbit(x); }
+#elif /* defined (__FreeBSD__) */ ( defined (__GNUC__) && defined (__APPLE__) )
+inline bool _Stl_is_nan_or_inf(double x) { return !finite(x); }
+inline bool _Stl_is_inf(double x)        {   return _Stl_is_nan_or_inf(x) && ! isnan(x); }
+inline bool _Stl_is_neg_inf(double x)    {   return _Stl_is_inf(x) && x < 0 ; }
+inline bool _Stl_is_neg_nan(double x)    { return isnan(x) && copysign(1., x) < 0 ; } 
+#elif defined( _AIX ) // JFA 11-Aug-2000
+bool _Stl_is_nan_or_inf(double x) { return isnan(x) || !finite(x); }
+bool _Stl_is_inf(double x)        { return !finite(x); }
+// bool _Stl_is_neg_inf(double x)    { return _class(x) == FP_MINUS_INF; }
+bool _Stl_is_neg_inf(double x)    { return _Stl_is_inf(x) && ( copysign(1., x) < 0 );  }
+bool _Stl_is_neg_nan(double x)    { return isnan(x) && ( copysign(1., x) < 0 );  }
+#elif defined (__ISCPP__)
+inline bool _Stl_is_nan_or_inf  (double x) { return _fp_isINF(x) || _fp_isNAN(x); }
+inline bool _Stl_is_inf         (double x) { return _fp_isINF(x); }
+inline bool _Stl_is_neg_inf     (double x) { return _fp_isINF(x) && x < 0; }
+inline bool _Stl_is_neg_nan     (double x) { return _fp_isNAN(x) && x < 0; }
+#elif defined(_CRAY)
+ #if defined(_CRAYIEEE)
+inline bool _Stl_is_nan_or_inf(double x) { return isnan(x) || isinf(x); }
+inline bool _Stl_is_inf(double x)        { return isinf(x); }
+inline bool _Stl_is_neg_inf(double x)    { return isinf(x) && signbit(x); }
+inline bool _Stl_is_neg_nan(double x)    { return isnan(x) && signbit(x); }
+ #else
+inline bool _Stl_is_nan_or_inf(double x) { return false; }
+inline bool _Stl_is_inf(double x)        { return false; }
+inline bool _Stl_is_neg_inf(double x)    { return false; }
+inline bool _Stl_is_neg_nan(double x)    { return false; }
+ #endif
+#elif ! defined (USE_SPRINTF_INSTEAD)
+# define USE_SPRINTF_INSTEAD
+#endif
+
+
+# ifndef  USE_SPRINTF_INSTEAD
+// Reentrant versions of floating-point conversion functions.  The argument
+// lists look slightly different on different operating systems, so we're
+// encapsulating the differences here.
+
+#if defined (__CYGWIN__) || defined(__DJGPP)
+  inline char* _Stl_ecvtR(double x, int n, int* pt, int* sign, char* buf)
+    { return ecvtbuf(x, n, pt, sign, buf); }
+  inline char* _Stl_fcvtR(double x, int n, int* pt, int* sign, char* buf)
+    { return fcvtbuf(x, n, pt, sign, buf); }
+# ifndef _STLP_NO_LONG_DOUBLE
+  inline char* _Stl_qecvtR(long double x, int n, int* pt, int* sign, char* buf)
+    { return ecvtbuf(x, n, pt, sign, buf); }
+  inline char* _Stl_qfcvtR(long double x, int n, int* pt, int* sign, char* buf)
+    { return fcvtbuf(x, n, pt, sign, buf); }
+# endif
+#elif defined (_STLP_USE_GLIBC)
+  inline char* _Stl_ecvtR(double x, int n, int* pt, int* sign, char* buf)
+    { return buf + ecvt_r(x, n, pt, sign, buf, NDIG+2); }
+  inline char* _Stl_fcvtR(double x, int n, int* pt, int* sign, char* buf)
+    { return buf + fcvt_r(x, n, pt, sign, buf, NDIG+2); }
+#  ifndef _STLP_NO_LONG_DOUBLE
+  inline char* _Stl_qecvtR(long double x, int n, int* pt, int* sign, char* buf)
+    { return buf + qecvt_r(x, n, pt, sign, buf, NDIG+2); }
+  inline char* _Stl_qfcvtR(long double x, int n, int* pt, int* sign, char* buf)
+    { return buf + qfcvt_r(x, n, pt, sign, buf, NDIG+2); }
+#  endif
+#elif defined (_STLP_SCO_OPENSERVER) || defined (__NCR_SVR)
+  inline char* _Stl_ecvtR(double x, int n, int* pt, int* sign, char* buf)
+    { return ecvt(x, n, pt, sign); }
+  inline char* _Stl_fcvtR(double x, int n, int* pt, int* sign, char* buf)
+    { return fcvt(x, n, pt, sign); }
+#  ifndef _STLP_NO_LONG_DOUBLE
+  inline char* _Stl_qecvtR(long double x, int n, int* pt, int* sign, char* buf)
+    { return ecvtl(x, n, pt, sign); }
+  inline char* _Stl_qfcvtR(long double x, int n, int* pt, int* sign, char* buf)
+    { return fcvtl(x, n, pt, sign); }
+#  endif
+#elif defined (__sun)
+  inline char* _Stl_ecvtR(double x, int n, int* pt, int* sign, char* buf)
+    { return econvert(x, n, pt, sign, buf); }
+  inline char* _Stl_fcvtR(double x, int n, int* pt, int* sign, char* buf)
+    { return fconvert(x, n, pt, sign, buf); }
+#  ifndef _STLP_NO_LONG_DOUBLE
+  inline char* _Stl_qecvtR(long double x, int n, int* pt, int* sign, char* buf)
+    { return qeconvert(&x, n, pt, sign, buf); }
+  inline char* _Stl_qfcvtR(long double x, int n, int* pt, int* sign, char* buf)
+    { return qfconvert(&x, n, pt, sign, buf); }
+#  endif
+#elif defined (__DECCXX) 
+  inline char* _Stl_ecvtR(double x, int n, int* pt, int* sign, char* buf)
+    { return (ecvt_r(x, n, pt, sign, buf, NDIG)==0 ? buf : 0); }
+  inline char* _Stl_fcvtR(double x, int n, int* pt, int* sign, char* buf)
+    { return (fcvt_r(x, n, pt, sign, buf, NDIG)==0 ? buf : 0); }
+#  ifndef _STLP_NO_LONG_DOUBLE
+// fbp : no "long double" conversions !
+  inline char* _Stl_qecvtR(long double x, int n, int* pt, int* sign, char* buf)
+    { return (ecvt_r((double)x, n, pt, sign, buf, NDIG)==0 ? buf : 0) ; }
+  inline char* _Stl_qfcvtR(long double x, int n, int* pt, int* sign, char* buf)
+    { return (fcvt_r((double)x, n, pt, sign, buf, NDIG)==0 ? buf : 0); }
+#  endif
+#elif defined (__hpux)
+   inline char* _Stl_ecvtR(double x, int n, int* pt, int* sign, char* buf)
+     { return ecvt(x, n, pt, sign); }
+   inline char* _Stl_fcvtR(double x, int n, int* pt, int* sign, char* buf)
+     { return fcvt(x, n, pt, sign); }
+# ifndef _STLP_NO_LONG_DOUBLE
+
+#  if defined( _REENTRANT ) && (defined(_PTHREADS_DRAFT4) || defined(PTHREAD_THREADS_MAX))
+   inline char* _Stl_qecvtR(long double x, int n, int* pt, int* sign, char* buf)
+     { return (_ldecvt_r(*(long_double*)&x, n, pt, sign, buf, NDIG+2)==0 ? buf : 0); }
+   inline char* _Stl_qfcvtR(long double x, int n, int* pt, int* sign, char* buf)
+     { return (_ldfcvt_r(*(long_double*)&x, n, pt, sign, buf, NDIG+2)==0 ? buf : 0); }
+#  else
+   inline char* _Stl_qecvtR(long double x, int n, int* pt, int* sign, char* buf)
+     { return _ldecvt(*(long_double*)&x, n, pt, sign); }
+   inline char* _Stl_qfcvtR(long double x, int n, int* pt, int* sign, char* buf)
+     { return _ldfcvt(*(long_double*)&x, n, pt, sign); }
+#  endif
+# endif
+#elif defined (_AIX)
+  inline char* _Stl_ecvtR(double x, int n, int* pt, int* sign, char* buf)
+    { LOCK_CVT RETURN_CVT(ecvt, x, n, pt, sign, buf) }
+  inline char* _Stl_fcvtR(double x, int n, int* pt, int* sign, char* buf)
+    { LOCK_CVT RETURN_CVT(fcvt, x, n, pt, sign, buf) }
+# ifndef _STLP_NO_LONG_DOUBLE
+  inline char* _Stl_qecvtR(long double x, int n, int* pt, int* sign, char* buf)
+    { LOCK_CVT RETURN_CVT(ecvt, x, n, pt, sign, buf) }
+  inline char* _Stl_qfcvtR(long double x, int n, int* pt, int* sign, char* buf)
+    { LOCK_CVT RETURN_CVT(fcvt, x, n, pt, sign, buf) }
+# endif
+#elif defined (__unix)  && !defined(__FreeBSD__)  && !defined(__NetBSD__) && !defined(__APPLE__) && !defined(_CRAY)
+  inline char* _Stl_ecvtR(double x, int n, int* pt, int* sign, char* buf)
+    { return ecvt_r(x, n, pt, sign, buf); }
+  inline char* _Stl_fcvtR(double x, int n, int* pt, int* sign, char* buf)
+    { return fcvt_r(x, n, pt, sign, buf); }
+# ifndef _STLP_NO_LONG_DOUBLE
+  inline char* _Stl_qecvtR(long double x, int n, int* pt, int* sign, char* buf)
+    { return qecvt_r(x, n, pt, sign, buf); }
+  inline char* _Stl_qfcvtR(long double x, int n, int* pt, int* sign, char* buf)
+    { return qfcvt_r(x, n, pt, sign, buf); }
+#  endif
+#elif defined (_MSC_VER) || defined (__MINGW32__) || defined (__BORLANDC__)
+// those guys claim _cvt functions being reentrant.
+inline char* _Stl_ecvtR(double x, int n, int* pt, int* sign, char* buf) {  return _ecvt(x, n, pt, sign); }
+inline char* _Stl_fcvtR(double x, int n, int* pt, int* sign, char* buf) { return _fcvt(x, n, pt, sign); }
+# ifndef _STLP_NO_LONG_DOUBLE
+inline char* _Stl_qecvtR(long double x, int n, int* pt, int* sign, char* buf) { return _ecvt((double)x, n, pt, sign); }
+inline char* _Stl_qfcvtR(long double x, int n, int* pt, int* sign, char* buf) { return _fcvt((double)x, n, pt, sign); }
+# endif
+#elif defined (__ISCPP__)
+inline char* _Stl_ecvtR(double x, int n, int* pt, int* sign, char* buf)
+{ return _fp_ecvt( x, n, pt, sign, buf); }
+
+inline char* _Stl_fcvtR(double x, int n, int* pt, int* sign, char* buf)
+{ return _fp_fcvt(x, n, pt, sign, buf); }
+
+# ifndef _STLP_NO_LONG_DOUBLE
+inline char* _Stl_qecvtR(long double x, int n, int* pt, int* sign, char* buf)
+{ return _fp_ecvt( x, n, pt, sign, buf); }
+
+inline char* _Stl_qfcvtR(long double x, int n, int* pt, int* sign, char* buf)
+{ return _fp_fcvt(x, n, pt, sign, buf); }
+# endif
+#elif defined (__MRC__) || defined(__SC__) || defined(_CRAY)
+inline char* _Stl_ecvtR(double x, int n, int* pt, int* sign, char* )
+{ return ecvt( x, n, pt, sign ); }
+inline char* _Stl_fcvtR(double x, int n, int* pt, int* sign, char* )
+{ return fcvt(x, n, pt, sign); }
+#ifndef _STLP_NO_LONG_DOUBLE
+inline char* _Stl_qecvtR(long double x, int n, int* pt, int* sign, char* )
+{ return ecvt( x, n, pt, sign ); }
+inline char* _Stl_qfcvtR(long double x, int n, int* pt, int* sign, char* )
+{ return fcvt(x, n, pt, sign); }
+#endif
+#endif
+
+
+//----------------------------------------------------------------------
+// num_put
+
+// Helper functions for _M_do_put_float
+
+// __format_float formats a mantissa and exponent as returned by
+// one of the conversion functions (ecvt_r, fcvt_r, qecvt_r, qfcvt_r)
+// according to the specified precision and format flags.  This is
+// based on doprnt but is much simpler since it is concerned only
+// with floating point input and does not consider all formats.  It
+// also does not deal with blank padding, which is handled by
+// __copy_float_and_fill. 
+
+void __format_float_scientific(char * buf, const char * bp, 
+			       int decpt, int sign, bool is_zero,
+			       ios_base::fmtflags flags,
+			       int precision, bool /* islong */)
+{
+  char * suffix;
+  char expbuf[MAXESIZ + 2];
+  // sign if required
+  if (sign)
+    *buf++ = '-';
+  else if (flags & ios_base::showpos)
+    *buf++ = '+';
+  
+  // first digit of mantissa
+  *buf++ = *bp++;
+
+  // decimal point if required
+  if (precision != 0 || flags & ios_base::showpoint)
+    *buf++ = '.';
+  // rest of mantissa
+  int rz = precision;
+  while (rz-- > 0 && *bp != 0)
+    *buf++ = *bp++;
+
+  // exponent
+  *(suffix = &expbuf[MAXESIZ]) = 0;
+  if (!is_zero) {
+    int nn = decpt - 1;
+    if (nn < 0)
+      nn = -nn;
+    for (; nn > 9; nn /= 10)
+      *--suffix = (char) todigit(nn % 10);
+    *--suffix = (char) todigit(nn);
+  }
+  	
+  // prepend leading zeros to exponent
+  while (suffix > &expbuf[MAXESIZ - 2])
+    *--suffix = '0';
+  
+  // put in the exponent sign
+  *--suffix = (char) ((decpt > 0 || is_zero ) ? '+' : '-');
+  
+  // put in the e
+  *--suffix = flags & ios_base::uppercase ? 'E' : 'e';
+
+  // copy the suffix
+  strcpy(buf, suffix);
+}
+
+static inline 
+void __flush_static_buf(string &buf, 
+                        char *sbeginbuf, char *sendbuf, char *&scurpos) {
+  if (scurpos == sendbuf) {
+    buf.append(sbeginbuf, sendbuf);
+    scurpos = sbeginbuf;
+  }
+}
+  
+void __format_float_fixed(string &buf, const char * bp,
+			  int decpt, int sign, bool /* x */,
+			  ios_base::fmtflags flags,
+			  int precision, bool islong )
+{
+  char static_buf[128];
+  char *sbuf = static_buf;
+  char *sendbuf = static_buf + sizeof(static_buf);
+
+  if (sign && decpt > -precision && *bp != 0)
+    *sbuf++ = '-';
+  else if (flags & ios_base::showpos)
+    *sbuf++ = '+';
+  
+  int rzero   = 0;
+  int nn      = decpt;
+  int k       = 0;
+  int maxfsig = islong ? 2*MAXFSIG : MAXFSIG;
+
+  do {
+    *sbuf++ = (char) ((nn <= 0 || *bp == 0 || k >= maxfsig) ?
+      '0' : (k++, *bp++));
+    __flush_static_buf(buf, static_buf, sendbuf, sbuf);
+  } while (--nn > 0);
+
+  // decimal point if needed
+  if (flags & ios_base::showpoint || precision > 0) {
+    *sbuf++ = '.';
+    __flush_static_buf(buf, static_buf, sendbuf, sbuf);
+  }
+
+  // digits after decimal point if any
+  nn = (min) (precision, MAXFCVT);
+  if (precision > nn)
+    rzero = precision - nn;
+  while (--nn >= 0) {
+    *sbuf++ = (++decpt <= 0 || *bp == '\0' || k >= maxfsig)
+      		? '0' : (k++, *bp++);
+    __flush_static_buf(buf, static_buf, sendbuf, sbuf);
+  }
+
+  // trailing zeros if needed
+  while (rzero-- > 0) {
+    *sbuf++ = '0';
+    __flush_static_buf(buf, static_buf, sendbuf, sbuf);
+  }
+  buf.append(static_buf, sbuf);
+}
+
+
+void __format_nan_or_inf(char * buf, double x,
+			 ios_base::fmtflags flags)
+{
+  static const char* inf[2] = { "inf", "Inf" };
+  static const char* nan[2] = { "nan", "NaN" };
+  const char** inf_or_nan = 0;
+  if (_Stl_is_inf((double)x)) {            // Infinity
+    inf_or_nan = inf;
+    if (_Stl_is_neg_inf((double)x))
+      *buf++ = '-';
+    else if (flags & ios_base::showpos)
+      *buf++ = '+';
+  }
+  else {                      // NaN
+    inf_or_nan = nan;
+    if (_Stl_is_neg_nan((double)x))
+      *buf++ = '-';
+    else if (flags & ios_base::showpos)
+      *buf++ = '+';
+  }
+  strcpy(buf, flags & ios_base::uppercase ? inf_or_nan[1] : inf_or_nan[0]);  
+}
+
+template <class max_double_type>
+static inline 
+void __format_float(string &buf, const char * bp,
+                    int decpt, int sign, max_double_type x,
+                    ios_base::fmtflags flags,
+                    int precision, bool islong)
+{
+  char static_buf[128];
+  // Output of infinities and NANs does not depend on the format flags
+  if (_Stl_is_nan_or_inf((double)x)) {       // Infinity or NaN
+    __format_nan_or_inf(static_buf, x, flags);
+    buf = static_buf;
+  } 
+  else {                        // representable number
+    switch (flags & ios_base::floatfield) {
+    case ios_base::scientific:
+      __format_float_scientific(static_buf, bp, decpt, sign, x == 0.0, flags,
+                                precision, islong);
+      buf = static_buf;
+      break;
+      
+    case ios_base::fixed:
+      __format_float_fixed(buf, bp, decpt, sign, true, flags,
+                           precision, islong);
+      break;
+      
+    default: // g format
+      // establish default precision
+      if (flags & ios_base::showpoint || precision > 0) {
+        if (precision == 0) precision = 1;
+      }
+      else
+        precision = 6;
+      
+      // reset exponent if value is zero
+      if (x == 0)
+        decpt = 1;
+      
+      int kk = precision;
+      if (!(flags & ios_base::showpoint)) {
+        size_t n = strlen(bp);
+        if (n < kk)
+          kk = (int)n;
+        while (kk >= 1 && bp[kk-1] == '0')
+          --kk;
+      }
+      
+      if (decpt < -3 || decpt > precision) {
+        precision = kk - 1;
+        __format_float_scientific(static_buf, bp, decpt, sign, x == 0,
+                                  flags, precision, islong);
+        buf = static_buf;
+      }
+      else {
+        precision = kk - decpt;
+        __format_float_fixed(buf, bp, decpt, sign, true,
+                             flags, precision, islong);
+      }
+      break;
+    } /* switch */
+  } /* else */
+}
+
+# else
+// Creates a format string for sprintf()
+static int fill_fmtbuf(char* fmtbuf, ios_base::fmtflags flags, char long_modifier)
+{
+  fmtbuf[0] = '%';
+  int i = 1;
+
+  if (flags & ios_base::showpos)
+    fmtbuf[i++] = '+';
+
+  if (flags & ios_base::showpoint)
+    fmtbuf[i++] = '#';
+
+  fmtbuf[i++] = '.';
+  fmtbuf[i++] = '*';
+  
+  if (long_modifier)
+    fmtbuf[i++] = long_modifier;
+
+  switch (flags & ios_base::floatfield)
+    {
+    case ios_base::scientific:
+      fmtbuf[i++] = (flags & ios_base::uppercase) ?  'E' : 'e';      
+      break;
+    case ios_base::fixed:
+#if defined (__FreeBSD__)
+      fmtbuf[i++] = 'f';
+#else
+      fmtbuf[i++] = (flags & ios_base::uppercase) ? 'F' : 'f'; 
+#endif
+      break;
+    default:
+      fmtbuf[i++] = (flags & ios_base::uppercase) ?  'G' : 'g';      
+      break;
+    }
+
+  fmtbuf[i] = 0;
+  return i;
+}
+# endif  /* USE_SPRINTF_INSTEAD */
+
+
+_STLP_EXP_DECLSPEC void  _STLP_CALL
+__write_float(string &buf, ios_base::fmtflags flags, int precision,
+              double x)
+{
+# ifdef USE_SPRINTF_INSTEAD
+  char static_buf[256+10];//+2 - 10/1/07
+  char fmtbuf[32];
+  fill_fmtbuf(fmtbuf, flags, 0);
+  sprintf(static_buf, fmtbuf, precision, x);    
+  // we should be able to return static_buf + sprintf(), but we do not trust'em...
+  buf = static_buf;
+# else
+  char cvtbuf[NDIG+2];
+  char * bp;
+  int decpt, sign;
+
+  switch (flags & ios_base::floatfield) {
+  case ios_base::fixed:
+    bp = _Stl_fcvtR(x, (min) (precision, MAXFCVT), &decpt, &sign, cvtbuf);
+    break;
+  case ios_base::scientific :
+    bp = _Stl_ecvtR(x, (min) (precision + 1, MAXECVT), &decpt, &sign, cvtbuf);
+    break;
+  default :
+    bp = _Stl_ecvtR(x, (min) (precision, MAXECVT), &decpt, &sign, cvtbuf);
+    break;
+  }
+  __format_float(buf, bp, decpt, sign, x, flags, precision, false);
+# endif
+
+}
+
+# ifndef _STLP_NO_LONG_DOUBLE
+_STLP_EXP_DECLSPEC void _STLP_CALL
+__write_float(string &buf, ios_base::fmtflags flags, int precision,
+              long double x)
+{
+# ifdef USE_SPRINTF_INSTEAD
+  char static_buf[128];
+  char fmtbuf[64];
+  int i = fill_fmtbuf(fmtbuf, flags, 'L');
+  sprintf(static_buf, fmtbuf, precision, x);    
+  // we should be able to return buf + sprintf(), but we do not trust'em...
+  buf = static_buf;
+# else
+  char cvtbuf[NDIG+2];
+  char * bp;
+  int decpt, sign;
+
+  switch (flags & ios_base::floatfield) {
+  case ios_base::fixed:
+    bp = _Stl_qfcvtR(x, (min) (precision, MAXFCVT), &decpt, &sign, cvtbuf);
+    break;
+  case ios_base::scientific :
+    bp = _Stl_qecvtR(x, (min) (precision + 1, MAXECVT),     &decpt, &sign, cvtbuf);
+    break;
+  default :
+    bp = _Stl_qecvtR(x, (min) (precision, MAXECVT), &decpt, &sign, cvtbuf);
+    break;
+  }
+  __format_float(buf, bp, decpt, sign, x, flags, precision, true);
+# endif
+}
+# endif
+
+
+# ifndef _STLP_NO_WCHAR_T
+
+_STLP_EXP_DECLSPEC wchar_t* _STLP_CALL
+__convert_float_buffer(const char* first, const char* last, wchar_t* out,
+                       const ctype<wchar_t>& ct, wchar_t dot)
+{
+  ct.widen(first, last, out);
+  if (ct.widen('.') != dot)
+    replace(out, out + (last - first), ct.widen('.'), dot);
+  return out + (last - first);
+}
+
+# endif
+
+_STLP_EXP_DECLSPEC void _STLP_CALL
+__adjust_float_buffer(char* first, char* last, char dot)
+{
+  if ('.' != dot)
+    replace(first, last, '.', dot);
+}
+
+_STLP_END_NAMESPACE
+
+// Local Variables:
+// mode:C++
+// End: