Find the first character in the string that is not in CharSet
<boost/url/grammar/charset.hpp>
template<CharSet CS>
char const*
find_if_not(
    char const const* first,
    char const const* last,
    CS const& cs) noexcept;
Throws nothing.
last.
| Name | Description | 
|---|---|
| first | A pointer to the first character in the string to search. | 
| last | A pointer to one past the last character in the string to search. | 
| cs | The character set to use. | 
find_if_not.