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

Subject: Re: [boost] [Convert] std::isspace requires unsigned #28
From: Gavin Lambert (gavinl_at_[hidden])
Date: 2017-03-21 00:43:03

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.

And as Glen suggests, simple overloads seem tidier.