Added some tests for try_lexical_convert and fixed some issues.

include/boost/lexical_cast.hpp

@@ -1394,14 +1394,7 @@ namespace boost {
             }
 
             template<typename InputStreamable>
-#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
-            bool shl_input_streamable(InputStreamable&& input) {
-                typedef InputStreamable&& forward_type;
-#else
             bool shl_input_streamable(InputStreamable& input) {
-                typedef InputStreamable& forward_type;
-#endif // BOOST_NO_CXX11_RVALUE_REFERENCES
-
 #if defined(BOOST_NO_STRINGSTREAM) || defined(BOOST_NO_STD_LOCALE)
                 // If you have compilation error at this point, than your STL library
                 // does not support such conversions. Try updating it.
@@ -1412,7 +1405,7 @@ namespace boost {
                 out_stream.exceptions(std::ios::badbit);
                 try {
 #endif
-                bool const result = !(out_stream << static_cast<forward_type>(input)).fail();
+                bool const result = !(out_stream << input).fail();
                 const buffer_t* const p = static_cast<buffer_t*>(
                     static_cast<std::basic_streambuf<CharT, Traits>*>(out_stream.rdbuf())
                 );
@@ -1673,7 +1666,6 @@ namespace boost {
                 return ((*this) << reinterpret_cast<boost::array<C, N> const& >(input)); 
             }
 #endif
-            
             template <class InStreamable>
             bool operator<<(const InStreamable& input)  { return shl_input_streamable(input); }
         };
@@ -2081,21 +2073,14 @@ namespace boost {
                 BOOST_DEDUCED_TYPENAME stream_trait::traits
             > o_interpreter_type;
 
-#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
-            template <class T>
-            static inline bool try_convert(T&& arg, Target& result) {
-                typedef T&& forward_type;
-#else
             static inline bool try_convert(const Source& arg, Target& result) {
-                typedef const Source& forward_type;
-#endif
                 i_interpreter_type i_interpreter;
 
                 // Disabling ADL, by directly specifying operators.
                 //
                 // For compilers with perfect forwarding `static_cast<forward_type>(arg)` is
                 // eqaul to `std::forward<T>(arg)`.
-                if (!(i_interpreter.operator <<(static_cast<forward_type>(arg))))
+                if (!(i_interpreter.operator <<(arg)))
                     return false;
 
                 o_interpreter_type out(i_interpreter.cbegin(), i_interpreter.cend());
@@ -2263,6 +2248,7 @@ namespace boost {
         };
     }
 
+    namespace conversion { namespace detail {
 
 #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
         template <typename Target, typename Source>
@@ -2315,12 +2301,31 @@ namespace boost {
             return caster_type::try_convert(static_cast<forward_type>(arg), result);
         }
 
+        template <typename Target, typename CharacterT>
+        inline bool try_lexical_convert(const CharacterT* chars, std::size_t count, Target& result)
+        {
+            BOOST_STATIC_ASSERT_MSG(
+                boost::detail::is_character<CharacterT>::value,
+                "This overload of try_lexical_convert is meant to be used only with arrays of characters."
+            );
+            return ::boost::conversion::detail::try_lexical_convert(
+                ::boost::iterator_range<const CharacterT*>(chars, chars + count), result
+            );
+        }
+
+    }} // namespace conversion::detail
+
+    namespace conversion {
+        // ADL barrier
+        using ::boost::conversion::detail::try_lexical_convert;
+    }
+
     template <typename Target, typename Source>
     inline Target lexical_cast(const Source &arg)
     {
         Target result;
 
-        if (!try_lexical_convert(arg, result))
+        if (!boost::conversion::detail::try_lexical_convert(arg, result))
             BOOST_LCAST_THROW_BAD_CAST(Source, Target);
 
         return result;
@@ -2334,14 +2339,6 @@ namespace boost {
         );
     }
 
-    template <typename Target>
-    inline bool try_lexical_convert(const char* chars, std::size_t count, Target& result)
-    {
-        return ::boost::try_lexical_convert(
-            ::boost::iterator_range<const char*>(chars, chars + count), result
-        );
-    }
-
     template <typename Target>
     inline Target lexical_cast(const unsigned char* chars, std::size_t count)
     {
@@ -2350,14 +2347,6 @@ namespace boost {
         );
     }
 
-    template <typename Target>
-    inline bool try_lexical_convert(const unsigned char* chars, std::size_t count, Target& result)
-    {
-        return ::boost::try_lexical_convert(
-            ::boost::iterator_range<const unsigned char*>(chars, chars + count), result
-        );
-    }
-
     template <typename Target>
     inline Target lexical_cast(const signed char* chars, std::size_t count)
     {
@@ -2366,14 +2355,6 @@ namespace boost {
         );
     }
 
-    template <typename Target>
-    inline bool try_lexical_convert(const signed char* chars, std::size_t count, Target& result)
-    {
-        return ::boost::try_lexical_convert(
-            ::boost::iterator_range<const signed char*>(chars, chars + count), result
-        );
-    }
-
 #ifndef BOOST_LCAST_NO_WCHAR_T
     template <typename Target>
     inline Target lexical_cast(const wchar_t* chars, std::size_t count)
@@ -2382,14 +2363,6 @@ namespace boost {
             ::boost::iterator_range<const wchar_t*>(chars, chars + count)
         );
     }
-
-    template <typename Target>
-    inline bool try_lexical_convert(const wchar_t* chars, std::size_t count, Target& result)
-    {
-        return ::boost::try_lexical_convert(
-            ::boost::iterator_range<const wchar_t*>(chars, chars + count), result
-        );
-    }
 #endif
 #ifndef BOOST_NO_CXX11_CHAR16_T
     template <typename Target>
@@ -2399,14 +2372,6 @@ namespace boost {
             ::boost::iterator_range<const char16_t*>(chars, chars + count)
         );
     }
-
-    template <typename Target>
-    inline bool try_lexical_convert(const char16_t* chars, std::size_t count, Target& result)
-    {
-        return ::boost::try_lexical_convert(
-            ::boost::iterator_range<const char16_t*>(chars, chars + count), result
-        );
-    }
 #endif
 #ifndef BOOST_NO_CXX11_CHAR32_T
     template <typename Target>
@@ -2416,14 +2381,6 @@ namespace boost {
             ::boost::iterator_range<const char32_t*>(chars, chars + count)
         );
     }
-
-    template <typename Target>
-    inline bool try_lexical_convert(const char32_t* chars, std::size_t count, Target& result)
-    {
-        return ::boost::try_lexical_convert(
-            ::boost::iterator_range<const char32_t*>(chars, chars + count), result
-        );
-    }
 #endif
 
 } // namespace boost

test/Jamfile.v2

@@ -62,6 +62,7 @@ test-suite conversion
     [ run lexical_cast_stream_traits_test.cpp ]
     [ compile-fail lexical_cast_to_pointer_test.cpp ]
     [ run lexical_cast_filesystem_test.cpp ../../filesystem/build//boost_filesystem/<link>static ]
+    [ run lexical_cast_try_lexical_convert.cpp ]
   ;
 
 # Assuring that examples compile and run. Adding sources from `example` directory to the `conversion` test suite. 

test/lexical_cast_try_lexical_convert.cpp

@@ -0,0 +1,78 @@
+//  Unit test for boost::lexical_cast.
+//
+//  See http://www.boost.org for most recent version, including documentation.
+//
+//  Copyright Antony Polukhin, 2014.
+//
+//  Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt).
+
+#include <boost/config.hpp>
+
+#include <boost/lexical_cast.hpp>
+#include <boost/test/unit_test.hpp>
+
+using namespace boost;
+
+void try_uncommon_cases()
+{
+    std::string sres;
+    const bool res1 = conversion::try_lexical_convert(std::string("Test string"), sres);
+    BOOST_CHECK(res1);
+    BOOST_CHECK_EQUAL(sres, "Test string");
+
+    volatile int vires;
+    const bool res2 = conversion::try_lexical_convert(100, vires);
+    BOOST_CHECK(res2);
+    BOOST_CHECK_EQUAL(vires, 100);
+
+    const bool res3 = conversion::try_lexical_convert("Test string", sres);
+    BOOST_CHECK(res3);
+    BOOST_CHECK_EQUAL(sres, "Test string");
+
+    const bool res4 = conversion::try_lexical_convert("Test string", sizeof("Test string") - 1, sres);
+    BOOST_CHECK(res4);
+    BOOST_CHECK_EQUAL(sres, "Test string");
+
+    int ires;
+    BOOST_CHECK(!conversion::try_lexical_convert("Test string", ires));
+    BOOST_CHECK(!conversion::try_lexical_convert(1.1, ires));
+    BOOST_CHECK(!conversion::try_lexical_convert(-1.9, ires));
+    BOOST_CHECK(!conversion::try_lexical_convert("1.1", ires));
+    BOOST_CHECK(!conversion::try_lexical_convert("1000000000000000000000000000000000000000", ires));
+}
+
+
+void try_common_cases()
+{
+    int ires = 0;
+    const bool res1 = conversion::try_lexical_convert(std::string("100"), ires);
+    BOOST_CHECK(res1);
+    BOOST_CHECK_EQUAL(ires, 100);
+
+    ires = 0;
+    const bool res2 = conversion::try_lexical_convert("-100", ires);
+    BOOST_CHECK(res2);
+    BOOST_CHECK_EQUAL(ires, -100);
+
+    float fres = 1.0f;
+    const bool res3 = conversion::try_lexical_convert("0.0", fres);
+    BOOST_CHECK(res3);
+    BOOST_CHECK_EQUAL(fres, 0.0f);
+
+    fres = 1.0f;
+    const bool res4 = conversion::try_lexical_convert("0.0", sizeof("0.0") - 1, fres);
+    BOOST_CHECK(res4);
+    BOOST_CHECK_EQUAL(fres, 0.0f);
+}
+
+unit_test::test_suite *init_unit_test_suite(int, char *[])
+{
+    unit_test::test_suite *suite =
+        BOOST_TEST_SUITE("Tests for try_lexical_convert");
+    suite->add(BOOST_TEST_CASE(&try_uncommon_cases));
+    suite->add(BOOST_TEST_CASE(&try_common_cases));
+
+    return suite;
+}