From 21e9e0d39724629471e4626fd027860f592d0e75 Mon Sep 17 00:00:00 2001
From: Markus Gans <guru@server.home.net>
Date: Tue, 30 Jun 2015 00:21:50 +0200
Subject: [PATCH] Class FString: improve floating point exception handling

---
 src/fstring.cpp  | 20 ++++++++++++++++----
 src/fstring.h    |  5 +----
 test/fstring.cpp |  9 +++++----
 3 files changed, 22 insertions(+), 12 deletions(-)

diff --git a/src/fstring.cpp b/src/fstring.cpp
index f9beedcf..b85d10ff 100644
--- a/src/fstring.cpp
+++ b/src/fstring.cpp
@@ -965,7 +965,7 @@ long FString::toLong() const
     if (  num > tenth_limit
        || (num == tenth_limit && d > tenth_limit_digit) )
     {
-      throw std::out_of_range ("overflow");
+      throw std::overflow_error ("overflow");
     }
     num = (num<<3)+(num<<1) + d;  // (10 * num) + d
     p++;
@@ -1009,7 +1009,7 @@ uLong FString::toULong() const
     if (  num > tenth_limit
        || (num == tenth_limit && d > tenth_limit_digit) )
     {
-      throw std::out_of_range ("overflow");
+      throw std::overflow_error ("overflow");
     }
     num = (num<<3)+(num<<1) + d;  // (10 * num) + d
     p++;
@@ -1021,6 +1021,18 @@ uLong FString::toULong() const
   return num;
 }
 
+//----------------------------------------------------------------------
+float FString::toFloat() const
+{
+  double d;
+  d = this->toDouble();
+
+  if ( d > FLT_MAX  || d < FLT_MIN )
+    throw std::overflow_error ("overflow");
+
+  return float(d);
+}
+
 //----------------------------------------------------------------------
 double FString::toDouble() const
 {
@@ -1041,9 +1053,9 @@ double FString::toDouble() const
   if ( errno == ERANGE )
   {
     if ( ret >= HUGE_VAL || ret <= -HUGE_VAL )
-      throw std::out_of_range ("overflow");
+      throw std::overflow_error ("overflow");
     if ( ret == 0.0l )
-      throw std::out_of_range ("underflow");
+      throw std::underflow_error ("underflow");
   }
   return ret;
 }
diff --git a/src/fstring.h b/src/fstring.h
index 3a54ce88..0f53591e 100644
--- a/src/fstring.h
+++ b/src/fstring.h
@@ -10,6 +10,7 @@
 
 #include <cassert>
 #include <cerrno>  // for read errno
+#include <cfloat>
 #include <climits>
 #include <cmath>
 #include <cstdarg> // need for va_list, va_start and va_end
@@ -335,10 +336,6 @@ inline int FString::toInt() const
 inline uInt FString::toUInt() const
 { return uInt( toULong() ); }
 
-//----------------------------------------------------------------------
-inline float FString::toFloat() const
-{ return float( toDouble() ); }
-
 //----------------------------------------------------------------------
 inline std::vector<FString> FString::split (std::wstring& s)
 { return split(FString(s)); }
diff --git a/test/fstring.cpp b/test/fstring.cpp
index 9617e3a4..054bd79a 100644
--- a/test/fstring.cpp
+++ b/test/fstring.cpp
@@ -140,9 +140,9 @@ int main (int, char**)
   {
     std::cerr << "Invalid argument: " << ex.what() << std::endl;
   }
-  catch (const std::out_of_range& ex)
+  catch (const std::exception& ex)
   {
-    std::cerr << "Out of range: " << ex.what() << std::endl;
+    std::cerr << "Arithmetic error: " << ex.what() << std::endl;
   }
 
   setlocale(LC_NUMERIC, "C");
@@ -156,10 +156,11 @@ int main (int, char**)
   {
     std::cerr << "Invalid argument: " << ex.what() << std::endl;
   }
-  catch (const std::out_of_range& ex)
+  catch (const std::exception& ex)
   {
-    std::cerr << "Out of range: " << ex.what() << std::endl;
+    std::cerr << "Arithmetic error: " << ex.what() << std::endl;
   }
+
   FString num1, num2, num3;
   num1.setNumber(137);
   num2.setNumber(-512);