Boost C++ Libraries: Ticket #4649: token_functions.hpp (220) : fix for warning C4127 conditional expression is constant

Wed, 15 Sep 2010 10:40:56 GMT

I just realised that the problem also affects ispunct too.

Perhaps the following solution?

Add:

#if !defined(BOOST_NO_CWCTYPE)
  struct is_space
  {
    template <typename char_type>
    static bool wchar_func(char_type c) { return std::iswspace(c) != 0; }
    template <typename char_type>
    static bool char_func(char_type c) { return std::isspace(c) != 0; }
  };
  struct is_punct
  {
    template <typename char_type>
    static bool wchar_func(char_type c) { return std::iswpunct(c) != 0; }
    template <typename char_type>
    static bool char_func(char_type c) { return std::ispunct(c) != 0; }
  };
  template <typename function_pair, typename traits, size_t char_type_size>
  struct check
  {
    typedef typename traits::char_type char_type;
    static bool value_for(char_type c) { return function_pair::wchar_func(c); }
  };
  template <typename function_pair, typename traits>
  struct check<function_pair, traits, 1>
  {
    typedef typename traits::char_type char_type;
    static bool value_for(char_type c) { return function_pair::char_func(c); }
  };
#endif

And replace:

  if (sizeof(char_type) == 1)
    return std::isspace(c) != 0;
  else
    return std::iswspace(c) != 0;

with

  return check<is_space, traits, sizeof(char_type)>::value_for(c);

and replace

  if (sizeof(char_type) == 1)
    return std::ispunct(c) != 0;
  else
    return std::iswpunct(c) != 0;

with

  return check<is_punct, traits, sizeof(char_type)>::value_for(c);

rvalde@… — Mon, 17 Jan 2011 17:53:30 GMT

Looking to submit a bug for this issue, and I found this one. The issue hasn't been solved for 1.45 yet. I'll attached my solution, for if someone likes it.

attachment set

rvalde@… — Mon, 17 Jan 2011 17:54:30 GMT

attachment → token_functions.patch

Marshall Clow — Mon, 17 Jan 2011 21:25:06 GMT

I attempted to apply your patch; it did not apply cleanly. I merged it in by hand, and found that clang TOT complained about an extra 'typename'.

With that taken out, it compiles and passes the tests using gcc 4.2.1 and clang TOT.

Adjusted patch attached.

attachment set

Marshall Clow — Mon, 17 Jan 2011 21:25:30 GMT

attachment → 4649-mtc.patch

anonymous — Thu, 20 Jan 2011 12:13:28 GMT

Thanks Marshall, sorry for the inconveniences caused by a bad patch.

I think the adjusted patch is missing something. There's a remaining const expression "if (sizeof(char)==1)" in traits_extension::ispunct that should be removed.

    static bool ispunct(char_type c)
    {
#if !defined(BOOST_NO_CWCTYPE)
      return traits_extension_details<traits, sizeof(char_type)>::ispunct(c);
#else
      return static_cast< unsigned >(c) <= 255 && std::ispunct(c) != 0;
#endif
    }

Marshall Clow — Thu, 20 Jan 2011 14:31:39 GMT

Well, crud. You are correct. Updated patch attached.

attachment set

Marshall Clow — Thu, 20 Jan 2011 14:31:58 GMT

attachment → 4649-mtc-2.patch

Marshall Clow — Tue, 05 Apr 2011 17:33:53 GMT

(In [71006]) Applied patch; Refs #4649

status changed; resolution set

Marshall Clow — Mon, 11 Apr 2011 13:21:19 GMT

status new → closed
resolution → fixed

(In [71185]) Merge tokenizer fixes to release. Fixes #4649