Fix several corner case bugs in lexical_cast

[libs/core.git] / source / strings / lexicalcast.cpp

diff --git a/source/strings/lexicalcast.cpp b/source/strings/lexicalcast.cpp
index 782f4a8537adb05583c6e45e68c6b80620439142..ab83b110b432ba408f8bdfa3bd2fb53d3e848c8f 100644 (file)
--- a/source/strings/lexicalcast.cpp
+++ b/source/strings/lexicalcast.cpp
@@ -1,5 +1,6 @@
 #include <cmath>
 #include <limits>
+#include <msp/core/inttypes.h>
 #include "format.h"
 #include "lexicalcast.h"
 
@@ -13,20 +14,6 @@ template<typename T>
 struct IsSigned
 { enum { result = !(static_cast<T>(-1)>0) }; };
 
-template<typename T, bool f = (sizeof(T)>sizeof(unsigned long))>
-struct Temporary
-{ typedef unsigned long Type; };
-
-template<typename T>
-struct Temporary<T, true>
-{
-#ifdef WIN32
-       typedef __int64 Type;
-#else
-       typedef unsigned long long Type;
-#endif
-};
-
 /* Helper to avoid warnings about an unsigned type never being < 0 */
 template<typename T, bool f = IsSigned<T>::result>
 struct IsNegative
@@ -72,7 +59,7 @@ char *int_to_str(T v, const Fmt &f, char *end)
        const char *digits = (f.get_uppercase() ? udigits : ldigits);
        if(v)
        {
-               typename Temporary<T>::Type w = Absolute<T>::eval(v);
+               typename MatchingInt<T>::UnsignedType w = Absolute<T>::eval(v);
                while(w)
                {
                        *--ptr = digits[w%base];
@@ -250,7 +237,7 @@ string flt_to_str(T v, const Fmt &f)
        if(w>=10)
        {
                long double div = 1;
-               while(div*10<w)
+               while(div*10<=w)
                {
                        ++exp;
                        div *= 10;
@@ -270,6 +257,7 @@ string flt_to_str(T v, const Fmt &f)
 
        // Decide how to format the number
        unsigned digits;
+       unsigned leading_zeroes = 0;
        unsigned point = 1;
        bool showexp = false;
        if(mode==Fmt::FIXED)
@@ -292,15 +280,16 @@ string flt_to_str(T v, const Fmt &f)
                }
                else
                {
-                       point = max(exp, 0)+1;
                        if(exp<0)
-                               digits += -exp;
+                               leading_zeroes = -exp;
+                       else
+                               point = exp+1;
                }
        }
 
        // Apply rounding
        w += 5.0l/pow(10.0l, static_cast<long double>(digits));
-       if(w>10)
+       if(w>=10)
        {
                // Rounding bumped us to the next exponent, deal with it
                w /= 10;
@@ -311,13 +300,19 @@ string flt_to_str(T v, const Fmt &f)
                }
                if(!showexp)
                {
-                       ++digits;
-                       ++point;
+                       if(mode==Fmt::FIXED)
+                               ++digits;
+                       if(leading_zeroes)
+                               --leading_zeroes;
+                       else
+                               ++point;
                }
                else
                        ++exp;
        }
 
+       digits += leading_zeroes;
+
        // Create a buffer and start from the end
        unsigned size = max(f.get_width(), digits+8);
        char *buf = new char[size];
@@ -339,14 +334,17 @@ string flt_to_str(T v, const Fmt &f)
        {
                if(i==point)
                        *mptr++ = '.';
-               if(showexp || static_cast<int>(i)>=-exp)
+               if(!leading_zeroes)
                {
                        int digit = static_cast<int>(w);
                        *mptr++ = '0'+digit;
                        w = (w-digit)*10;
                }
                else
+               {
                        *mptr++ = '0';
+                       --leading_zeroes;
+               }
        }
 
        if(f.get_showpoint())
@@ -547,7 +545,7 @@ void operator<<(LexicalConverter &c, const char *s)
 { c.result(str_to_str(s, c.get_fmt())); }
 
 void operator<<(LexicalConverter &c, const void *p)
-{ c.result(int_to_str(reinterpret_cast<unsigned long>(p), c.get_fmt())); }
+{ c.result(int_to_str(reinterpret_cast<IntPtr>(p), c.get_fmt())); }
 
 
 /*** operator>> ***/