Determine if a string contains only alphanumeric characters (or a space)

Posted by dreamlax on Stack Overflow See other posts from Stack Overflow or by dreamlax
Published on 2010-05-28T05:47:27Z Indexed on 2010/05/28 5:51 UTC
Read the original article Hit count: 268

Filed under:
|
|
|

I'm learning C++ and I am writing a function that determines whether a string contains only alphanumeric characters and spaces. I suppose I am effectively testing whether it matches the regular expression ^[[:alnum:] ]+$ but without using regular expressions. I have seen a lot of algorithms revolve around iterators, so I tried to find a solution that made use of iterators, and this is what I have:

#include <algorithm>

static inline bool is_not_alnum_space(char c)
{
    return !(isalpha(c) || isdigit(c) || (c == ' '));
}

bool string_is_valid(const std::string &str)
{
    return find_if(str.begin(), str.end(), is_not_alnum_space) == str.end();
}

Is there a better solution, or a “more C++” way to do this?

© Stack Overflow or respective owner

Related posts about c++

Related posts about algorithm