Re: [boost] [Convert] std::isspace requires unsigned #28

Subject: Re: [boost] [Convert] std::isspace requires unsigned #28
From: Vladimir Batov (Vladimir.Batov_at_[hidden])
Date: 2017-03-21 00:46:05

On 2017-03-21 11:43, Gavin Lambert via Boost wrote:
> On 21/03/2017 13:16, Vladimir Batov via Boost wrote:
>> Damn confused.
>> 
>> WAS: std::isspace(ch);
>> THEN: std::isspace(static_cast<unsigned char>(ch));
>> 
>> THEN I realized I needed wchar_t support and therefore needed also
>> std::iswspace(). So, for such a seemingly trivial thing I ended up 
>> with
>> the following ugliness:
> [...]
>> That raises two questions.
>> 
>> 1) Is it really the only way to go or I went senile or fell behind
>> language-wise?
>> 2) What about std::iswspace? Does it also need static_cast?
>> 
>> Apologies for seemingly naive questions but I really feel startled.
> 
> I haven't verified but presumably
> std::char_traits<char/wchar_t>::to_int_type() would convert correctly
> for input to std::isspace/iswspace.

Thanks, Gavin, indeed I should have a dig in char_traits before 
re-inventing the wheel. Thanks.

What about iswspace()? Does it have the same problem as std::isspace(), 
i.e. needs an explicit cast? Seems unlikely...