Fix ambiguity while using lexical_cast with std::transform or other functions that may take a pointer to lexical_cast (refs #7421)

[SVN r83457]

include/boost/lexical_cast.hpp

@@ -2446,17 +2446,59 @@ namespace boost {
         return caster_type::lexical_cast_impl(arg);
     }
 
-    template <typename Target, typename CharType>
+    template <typename Target>
-    inline Target lexical_cast(const CharType* chars, std::size_t count)
+    inline Target lexical_cast(const char* chars, std::size_t count)
-    {
+     {
-        BOOST_STATIC_ASSERT_MSG(boost::detail::is_char_or_wchar<CharType>::value, 
+        return ::boost::lexical_cast<Target>(
-            "CharType must be a character or wide character type");
+            ::boost::iterator_range<const char*>(chars, chars + count)
-
-        return boost::lexical_cast<Target>(
-            boost::iterator_range<const CharType*>(chars, chars + count)
         );
     }
 
+
+    template <typename Target>
+    inline Target lexical_cast(const unsigned char* chars, std::size_t count)
+    {
+         return ::boost::lexical_cast<Target>(
+            ::boost::iterator_range<const unsigned char*>(chars, chars + count)
+         );
+     }
+
+    template <typename Target>
+    inline Target lexical_cast(const signed char* chars, std::size_t count)
+    {
+        return ::boost::lexical_cast<Target>(
+            ::boost::iterator_range<const signed char*>(chars, chars + count)
+        );
+    }
+
+#ifndef BOOST_LCAST_NO_WCHAR_T
+    template <typename Target>
+    inline Target lexical_cast(const wchar_t* chars, std::size_t count)
+    {
+        return ::boost::lexical_cast<Target>(
+            ::boost::iterator_range<const wchar_t*>(chars, chars + count)
+        );
+    }
+#endif
+#ifndef BOOST_NO_CHAR16_T
+    template <typename Target>
+    inline Target lexical_cast(const char16_t* chars, std::size_t count)
+    {
+        return ::boost::lexical_cast<Target>(
+            ::boost::iterator_range<const char16_t*>(chars, chars + count)
+        );
+    }
+#endif
+#ifndef BOOST_NO_CHAR32_T
+    template <typename Target>
+    inline Target lexical_cast(const char32_t* chars, std::size_t count)
+    {
+        return ::boost::lexical_cast<Target>(
+            ::boost::iterator_range<const char32_t*>(chars, chars + count)
+        );
+    }
+#endif
+
 } // namespace boost
 
 #else // #ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION

lexical_cast_test.cpp

@@ -36,6 +36,7 @@
 #include <boost/type_traits/integral_promotion.hpp>
 #include <string>
 #include <vector>
+#include <algorithm> // std::transform
 #include <memory>
 
 #if (defined(BOOST_HAS_LONG_LONG) || defined(BOOST_HAS_MS_INT64)) \
@@ -622,6 +623,10 @@ void test_getting_pointer_to_function()
     typedef std::string(*f3)(const int&);
     f3 p3 = &boost::lexical_cast<std::string, int>;
     BOOST_CHECK(p3);
+
+    std::vector<int> values;
+    std::vector<std::string> ret;
+    std::transform(values.begin(), values.end(), ret.begin(), boost::lexical_cast<std::string, int>);
 }