From: Pavol Droba (droba_at_[hidden])
Date: 2002-10-21 05:54:30
> well.. to do it right would require a bit more than that :)
>
> (preface : i'm in a c++ channel on irc, and this is code on our bot, but
> this is some of the code we have for this sorta thing, and i think it
> works rather well )
>
> //------code-----
> //tolower = applies tolower on a std::string
> #include <algorithm>
> #include <functional>
> #include <string>
> #include <cctype>
> std::string&
> tolower (std::string &s)
> {
> std::transform(s.begin(), s.end(),s.begin(),
> std::ptr_fun<int, int>(std::tolower));
> return s;
> }
> //tolower = applies tolower on a char* array
> #include <algorithm>
> #include <functional>
> #include <cctype>
> #include <cstring>
> char*
> tolower (char buf[], size_t n)
> {
> std::transform(buf, buf + n,buf,
> std::ptr_fun<int, int>(std::tolower));
> return buf;
> }
> inline char*
> tolower (char buf[])
> {
> return tolower(buf, std::strlen(buf));
> }
> //-----end code -----------
> we also have code for trim'ing a std::string, and for trim'ing a
> basic_string<>
> this is that code
>
> //---------code-------
>
> //rtrim = trims all spaces at the end of a string
> std::string&
> rtrim (std::string &s)
> {
> s.erase(std::find_if(s.rbegin(), s.rend(),
> std::not1(std::ptr_fun(std::isspace))).base(),
> s.end());
> return s;
> }
>
> // ltrim trims all spaces at the beginning of a string
> std::string&
> ltrim (std::string &s)
> {
> s.erase(s.begin(),
> std::find_if(s.begin(), s.end(),
> std::not1(std::ptr_fun(std::isspace))));
> return s;
> }
>
> // an isSpace functor to make bind2nd happy
> template< class charT >
> struct isspaceF : public std::binary_function< charT, std::locale,
> bool > {
> result_type operator ()( first_argument_type c, const
> second_argument_type& l ) const
> {
> return std::isspace( c, l );
> }
> };
>
> //ltrim-generic = same as ltrim but on a basic_string<>
> template< class charT, class T, class A >
> std::basic_string<charT,T,A>&
> ltrim( std::basic_string<charT,T,A>& s, const std::locale& l =
> std::locale() )
> {
> s.erase( s.begin(),
> std::find_if(s.begin(), s.end(),
> std::not1( std::bind2nd( isspaceF<charT>(), l ) ) ) );
> return s;
> }
> //rtrim-generic = same as rtrim on a basic_string<>
> template< class charT, class T, class A >
> std::basic_string<charT,T,A>&
> rtrim( std::basic_string<charT,T,A>& s,
> const std::locale& l = std::locale() )
> {
> s.erase(std::find_if(s.rbegin(), s.rend(),
> std::not1(std::bind2nd(
> isspaceF<charT>(),l))).base(), s.end());
> return s;
> }
>
> // trim = trims all spaces on both sides of a string
> std::string&
> trim (std::string &s)
> {
> return ltrim(rtrim(s));
> }
> //-----end code----------
>
> that code has been tested on vc6, vc7 , gcc2.x , and gcc 3.x , so i
> can't guarantee that other compilers will compile them
> properly
Thank you, this definitely brings some nice ideas, althoug there are
places I would rather use different strategy.
For instance, besides in-place modifications I'd like to support const variants
of functions.
Other extension is to support not only string like containters but at least all
sequences.
Pavol