From fd4b84807f184f5259afb89b18cdc288f48176b2 Mon Sep 17 00:00:00 2001
From: Dario Sassi <dario.sassi@egalware.com>
Date: Fri, 3 Jan 2025 12:16:52 +0100
Subject: [PATCH] Include : - modifiche a FromString con double per uso
 libreria fast_float.

---
 EGnStringUtils.h | 33 ++++++++++++++-------------------
 1 file changed, 14 insertions(+), 19 deletions(-)

diff --git a/EGnStringUtils.h b/EGnStringUtils.h
index 34002ac..6b828e1 100644
--- a/EGnStringUtils.h
+++ b/EGnStringUtils.h
@@ -15,6 +15,7 @@
 
 #include "/EgtDev/Include/EgtStringBase.h"
 #include "/EgtDev/Include/EgtNumCollection.h"
+#include "/EgtDev/Extern/fast_float/fast_float.h"
 #include <algorithm>
 #include <array>
 
@@ -123,6 +124,7 @@ ValidateDxfName( std::string& sName, bool bAdvanced)
 }
 
 //----------------------------------------------------------------------------
+#define FAST_FLOAT_FMT     fast_float::chars_format::general | fast_float::chars_format::allow_leading_plus | fast_float::chars_format::skip_white_space
 inline bool
 FromString( const std::string& sVal, int& nVal)
       { const char* pStart = sVal.c_str() ;
@@ -146,11 +148,8 @@ FromString( const std::string& sVal, bool& bVal)
         return true ; }
 inline bool
 FromString( const std::string& sVal, double& dVal)
-      { const char* pStart = sVal.c_str() ;
-        char* pStop ;
-        errno = 0 ;
-        dVal = strtod( pStart, &pStop) ;
-        return ( pStop != pStart  &&  errno == 0) ; }
+      { auto answer = fast_float::from_chars( sVal.data(), sVal.data() + sVal.size(), dVal, FAST_FLOAT_FMT) ;
+        return ( answer.ec == std::errc()  &&  answer.ptr != sVal.data()) ; }
 template <size_t size>
 bool FromString( const std::string& sVal, int (&nVal)[size])
       { const char* pStart = sVal.c_str() ;
@@ -166,29 +165,25 @@ bool FromString( const std::string& sVal, int (&nVal)[size])
       }
 template <size_t size>
 bool FromString( const std::string& sVal, double (&dVal)[size])
-      { const char* pStart = sVal.c_str() ;
-        char* pStop ;
-        errno = 0 ;
+      { const char* pFirst = sVal.data() ;
         for ( int i = 0 ; i < size ; ++ i) {
-           dVal[i] = strtod( pStart, &pStop) ;
-           if ( ( i < size - 1  &&  *pStop != ',')  ||  errno != 0)
+           auto answer = fast_float::from_chars( pFirst, sVal.data() + sVal.size(), dVal[i], FAST_FLOAT_FMT) ;
+           if ( answer.ec != std::errc()  ||  ( i < size - 1  &&  answer.ptr[0] != ','))
               return false ;
-           pStart = pStop + 1 ;
+           pFirst = answer.ptr + 1 ;
         }
-        return ( errno == 0) ;
+        return true ;
       }
 template <size_t size>
 bool FromString( const std::string& sVal, std::array<double,size>& dVal)
-      { const char* pStart = sVal.c_str() ;
-        char* pStop ;
-        errno = 0 ;
+      { const char* pFirst = sVal.data() ;
         for ( int i = 0 ; i < size ; ++ i) {
-           dVal[i] = strtod( pStart, &pStop) ;
-           if ( ( i < size - 1  &&  *pStop != ',')  ||  errno != 0)
+           auto answer = fast_float::from_chars( pFirst, sVal.data() + sVal.size(), dVal[i], FAST_FLOAT_FMT) ;
+           if ( answer.ec != std::errc()  ||  ( i < size - 1  &&  answer.ptr[0] != ','))
               return false ;
-           pStart = pStop + 1 ;
+           pFirst = answer.ptr + 1 ;
         }
-        return ( errno == 0) ;
+        return true ;
       }
 EGN_EXPORT bool FromString( const std::string& sVal, INTVECTOR& vnVal) ;
 EGN_EXPORT bool FromString( const std::string& sVal, DBLVECTOR& vdVal) ;