🐛 fixes crash in dump from static object (#359)

Merge branch 'feature/issue359' into develop

README.md

@@ -499,6 +499,8 @@ I deeply appreciate the help of the following people.
 - [ChristophJud](https://github.com/ChristophJud) overworked the CMake files to ease project inclusion.
 - [Vladimir Petrigo](https://github.com/vpetrigo) made a SFINAE hack more readable.
 - [Denis Andrejew](https://github.com/seeekr) fixed a grammar issue in the README file.
+- [Pierre-Antoine Lacaze](https://github.com/palacaze) found a subtle bug in the `dump()` function.
+- [TurpentineDistillery](https://github.com/TurpentineDistillery) pointed to [`std::locale::classic()`](http://en.cppreference.com/w/cpp/locale/locale/classic) to avoid too much locale joggling.
 
 Thanks a lot for helping out!
 

src/json.hpp

@@ -45,7 +45,7 @@ SOFTWARE.
 #include <iostream> // istream, ostream
 #include <iterator> // advance, begin, bidirectional_iterator_tag, distance, end, inserter, iterator, iterator_traits, next, random_access_iterator_tag, reverse_iterator
 #include <limits> // numeric_limits
-#include <locale> // locale, numpunct
+#include <locale> // locale
 #include <map> // map
 #include <memory> // addressof, allocator, allocator_traits, unique_ptr
 #include <numeric> // accumulate
@@ -122,26 +122,6 @@ struct has_mapped_type
         std::is_integral<decltype(detect(std::declval<T>()))>::value;
 };
 
-/*!
-@brief helper class to create locales with decimal point
-
-This struct is used a default locale during the JSON serialization. JSON
-requires the decimal point to be `.`, so this function overloads the
-`do_decimal_point()` function to return `.`. This function is called by
-float-to-string conversions to retrieve the decimal separator between integer
-and fractional parts.
-
-@sa https://github.com/nlohmann/json/issues/51#issuecomment-86869315
-@since version 2.0.0
-*/
-struct DecimalSeparator : std::numpunct<char>
-{
-    char do_decimal_point() const
-    {
-        return '.';
-    }
-};
-
 }
 
 /*!
@@ -2201,8 +2181,7 @@ class basic_json
     {
         std::stringstream ss;
         // fix locale problems
-        const static std::locale loc(std::locale(), new DecimalSeparator);
+        ss.imbue(std::locale::classic());
-        ss.imbue(loc);
 
         // 6, 15 or 16 digits of precision allows round-trip IEEE 754
         // string->float->string, string->double->string or string->long
@@ -5829,7 +5808,7 @@ class basic_json
         o.width(0);
 
         // fix locale problems
-        const auto old_locale = o.imbue(std::locale(std::locale(), new DecimalSeparator));
+        const auto old_locale = o.imbue(std::locale::classic());
         // set precision
 
         // 6, 15 or 16 digits of precision allows round-trip IEEE 754

src/json.hpp.re2c

@@ -45,7 +45,7 @@ SOFTWARE.
 #include <iostream> // istream, ostream
 #include <iterator> // advance, begin, bidirectional_iterator_tag, distance, end, inserter, iterator, iterator_traits, next, random_access_iterator_tag, reverse_iterator
 #include <limits> // numeric_limits
-#include <locale> // locale, numpunct
+#include <locale> // locale
 #include <map> // map
 #include <memory> // addressof, allocator, allocator_traits, unique_ptr
 #include <numeric> // accumulate
@@ -122,26 +122,6 @@ struct has_mapped_type
         std::is_integral<decltype(detect(std::declval<T>()))>::value;
 };
 
-/*!
-@brief helper class to create locales with decimal point
-
-This struct is used a default locale during the JSON serialization. JSON
-requires the decimal point to be `.`, so this function overloads the
-`do_decimal_point()` function to return `.`. This function is called by
-float-to-string conversions to retrieve the decimal separator between integer
-and fractional parts.
-
-@sa https://github.com/nlohmann/json/issues/51#issuecomment-86869315
-@since version 2.0.0
-*/
-struct DecimalSeparator : std::numpunct<char>
-{
-    char do_decimal_point() const
-    {
-        return '.';
-    }
-};
-
 }
 
 /*!
@@ -2201,8 +2181,7 @@ class basic_json
     {
         std::stringstream ss;
         // fix locale problems
-        const static std::locale loc(std::locale(), new DecimalSeparator);
+        ss.imbue(std::locale::classic());
-        ss.imbue(loc);
 
         // 6, 15 or 16 digits of precision allows round-trip IEEE 754
         // string->float->string, string->double->string or string->long
@@ -5829,7 +5808,7 @@ class basic_json
         o.width(0);
 
         // fix locale problems
-        const auto old_locale = o.imbue(std::locale(std::locale(), new DecimalSeparator));
+        const auto old_locale = o.imbue(std::locale::classic());
         // set precision
 
         // 6, 15 or 16 digits of precision allows round-trip IEEE 754