Using tolower in transform

[TheDD]

Hello,

i don't manage to use the tolower() function:

#include <algorithm>
#include <iostream>
#include <locale>
#include <string>

using std::cout;
using std::ctype;
using std::endl;
using std::locale;
using std::string;
using std::transform;
using std::use_facet;

typedef ctype< char > char_ctype_face t;

int
main()
{
locale loc("");
const char_ctype_face t& ct = use_facet< char_ctype_face t >(loc);
string str("Hello world.");

transform(str.b egin(), str.end(),
str.begin(), ct.tolower);

cout << str << endl;
return 0;
}

$ g++ -W -Wall -std=c++98 -pedantic tolower.cc
tolower.cc: In function `int main()':
tolower.cc:24: error: no matching function for call to
`transform(__gn u_cxx::__normal _iterator<char* , std::basic_stri ng<char,
std::char_trait s<char>, std::allocator< char> > >,
__gnu_cxx::__no rmal_iterator<c har*, std::basic_stri ng<char,
std::char_trait s<char>, std::allocator< char> > >,
__gnu_cxx::__no rmal_iterator<c har*, std::basic_stri ng<char,
std::char_trait s<char>, std::allocator< char> > >, <unknown type>)'

ct.tolower is <unknow type>

What am i doing wrong?

--
TheDD

[Victor Bazarov]

TheDD wrote:

Hello,

i don't manage to use the tolower() function:

#include <algorithm>
#include <iostream>
#include <locale>
#include <string>

using std::cout;
using std::ctype;
using std::endl;
using std::locale;
using std::string;
using std::transform;
using std::use_facet;

typedef ctype< char > char_ctype_face t;

int
main()
{
locale loc("");
const char_ctype_face t& ct = use_facet< char_ctype_face t >(loc);
string str("Hello world.");

transform(str.b egin(), str.end(),
str.begin(), ct.tolower);
Wouldn't

transform(str.b egin(), str.end(), str.begin(), tolower);

do the trick?

cout << str << endl;
return 0;
}

$ g++ -W -Wall -std=c++98 -pedantic tolower.cc
tolower.cc: In function `int main()':
tolower.cc:24: error: no matching function for call to
`transform(__gn u_cxx::__normal _iterator<char* , std::basic_stri ng<char,
std::char_trait s<char>, std::allocator< char> > >,
__gnu_cxx::__no rmal_iterator<c har*, std::basic_stri ng<char,
std::char_trait s<char>, std::allocator< char> > >,
__gnu_cxx::__no rmal_iterator<c har*, std::basic_stri ng<char,
std::char_trait s<char>, std::allocator< char> > >, <unknown type>)'

ct.tolower is <unknow type>

What am i doing wrong?

Not sure.

Victor

[TheDD]

Victor Bazarov wrote:

[...]

locale loc("");
const char_ctype_face t& ct = use_facet< char_ctype_face t >(loc);
string str("Hello world.");

transform(str.b egin(), str.end(),
str.begin(), ct.tolower);

Wouldn't

transform(str.b egin(), str.end(), str.begin(), tolower);

do the trick?

yes it does, thx a lot.

But in this case, i guess the used locale is "C". What can i do to use
another one?

--
TheDD

[Victor Bazarov]

TheDD wrote:

Victor Bazarov wrote:

[...]

locale loc("");
const char_ctype_face t& ct = use_facet< char_ctype_face t >(loc);
string str("Hello world.");

transform(str.b egin(), str.end(),
str.begin(), ct.tolower);

Wouldn't

transform(str.b egin(), str.end(), str.begin(), tolower);

do the trick?

yes it does, thx a lot.

But in this case, i guess the used locale is "C". What can i do to use
another one?

Good question. Could you temporarily set it as "global one to use"
somehow? I am not that familiar with locales, as you probably figured
out by now...

V

[TheDD]

Victor Bazarov wrote:

Good question. Could you temporarily set it as "global one to use"
somehow? I am not that familiar with locales, as you probably figured
out by now...

Well i can use:

locale::global( locale(""));

but it's not really great. I'm going to read the docs one more time :)

--
TheDD

[Victor Bazarov]

TheDD wrote:

i don't manage to use the tolower() function:

#include <algorithm>
#include <iostream>
#include <locale>
#include <string>

using std::cout;
using std::ctype;
using std::endl;
using std::locale;
using std::string;
using std::transform;
using std::use_facet;

typedef ctype< char > char_ctype_face t;

int
main()
{
locale loc("");
const char_ctype_face t& ct = use_facet< char_ctype_face t >(loc);
string str("Hello world.");

transform(str.b egin(), str.end(),
str.begin(), ct.tolower);
If you have to use a member function, try something like

std::transform( str.begin(), str.end(), str.begin(),
std::bind1st(st d::mem_fun(&cty pe<char>::tolow er), ct));

I couldn't get it to compile, but dig in that direction.

cout << str << endl;
return 0;
}

$ g++ -W -Wall -std=c++98 -pedantic tolower.cc
tolower.cc: In function `int main()':
tolower.cc:24: error: no matching function for call to
`transform(__gn u_cxx::__normal _iterator<char* , std::basic_stri ng<char,
std::char_trait s<char>, std::allocator< char> > >,
__gnu_cxx::__no rmal_iterator<c har*, std::basic_stri ng<char,
std::char_trait s<char>, std::allocator< char> > >,
__gnu_cxx::__no rmal_iterator<c har*, std::basic_stri ng<char,
std::char_trait s<char>, std::allocator< char> > >, <unknown type>)'

ct.tolower is <unknow type>

What am i doing wrong?

To use a member function, you need 'mem_fun'.

Victor

[rossum]

On Fri, 28 May 2004 22:18:50 +0200, TheDD <pa*********@pa s.de.spam.fr>
wrote:

Hello,

i don't manage to use the tolower() function:

#include <algorithm>
#include <iostream>
#include <locale>
#include <string>
#include <cstdlib>

using std::cout;
using std::ctype;
using std::endl;
using std::locale;
using std::string;
using std::transform;
using std::use_facet;

typedef ctype< char > char_ctype_face t;

int
main()
{
locale loc("");
const char_ctype_face t& ct = use_facet< char_ctype_face t >(loc);
string str("Hello world.");

transform(str.b egin(), str.end(),
str.begin(), ct.tolower);

cout << str << endl;
return 0;
}

$ g++ -W -Wall -std=c++98 -pedantic tolower.cc
tolower.cc: In function `int main()':
tolower.cc:2 4: error: no matching function for call to
`transform(__g nu_cxx::__norma l_iterator<char *, std::basic_stri ng<char,
std::char_trai ts<char>, std::allocator< char> > >,
__gnu_cxx::__n ormal_iterator< char*, std::basic_stri ng<char,
std::char_trai ts<char>, std::allocator< char> > >,
__gnu_cxx::__n ormal_iterator< char*, std::basic_stri ng<char,
std::char_trai ts<char>, std::allocator< char> > >, <unknown type>)'

ct.tolower is <unknow type>

What am i doing wrong?

You need to include a library that includes tolower.

rossum
(Who has done the same sort of thing more often than he cares to
remember.)
--

The Ultimate Truth is that there is no Ultimate Truth

[TheDD]

Le 28/05/2004 à 23:29:31, rossum <ro******@coldm ail.com> a écrit:

On Fri, 28 May 2004 22:18:50 +0200, TheDD <pa*********@pa s.de.spam.fr>
wrote:

Hello,

i don't manage to use the tolower() function:

#include <algorithm>
#include <iostream>
#include <locale>
#include <string>

#include <cstdlib>

using std::cout;
using std::ctype;
using std::endl;
using std::locale;
using std::string;
using std::transform;
using std::use_facet;

typedef ctype< char > char_ctype_face t;

int
main()
{
locale loc("");
const char_ctype_face t& ct = use_facet< char_ctype_face t >(loc);
string str("Hello world.");

transform(str.b egin(), str.end(),
str.begin(), ct.tolower);

cout << str << endl;
return 0;
}

$ g++ -W -Wall -std=c++98 -pedantic tolower.cc
tolower.cc: In function `int main()':
tolower.cc:24 : error: no matching function for call to
`transform(__ gnu_cxx::__norm al_iterator<cha r*, std::basic_stri ng<char,
std::char_tra its<char>, std::allocator< char> > >,
__gnu_cxx::__ normal_iterator <char*, std::basic_stri ng<char,
std::char_tra its<char>, std::allocator< char> > >,
__gnu_cxx::__ normal_iterator <char*, std::basic_stri ng<char,
std::char_tra its<char>, std::allocator< char> > >, <unknown type>)'

ct.tolower is <unknow type>

What am i doing wrong?

You need to include a library that includes tolower.

rossum
(Who has done the same sort of thing more often than he cares to
remember.)

same error message, doesn't seem to be that.

--
TheDD

[TheDD]

Victor Bazarov wrote:

If you have to use a member function, try something like

std::transform( str.begin(), str.end(), str.begin(),
std::bind1st(st d::mem_fun(&cty pe<char>::tolow er), ct));

I couldn't get it to compile, but dig in that direction.

Well i don't have a member function.

This works:

#include <algorithm>
#include <iostream>
#include <locale>
#include <string>
#include <functional>

using std::cout;
using std::endl;
using std::locale;
using std::string;
using std::transform;
using std::bind2nd;

struct s : std::binary_fun ction< char, locale, char >
{
char operator ()(char c, const locale & loc) const
{
/* use:
* template<typena me CharT>
* CharT std::tolower ( CharT c,
* const locale & __loc
* )
*/
return std::tolower(c, loc);
}
};

int
main()
{
locale loc("");
string str("Hello world.");

// use s operator ()
transform(str.b egin(), str.end(),
str.begin(), bind2nd(s(), loc));

cout << str << endl;
return 0;
}
but is really not classy.

--
TheDD

[Victor Bazarov]

"TheDD" <pa*********@pa s.de.spam.fr> wrote...

Victor Bazarov wrote:

If you have to use a member function, try something like

std::transform( str.begin(), str.end(), str.begin(),
std::bind1st(st d::mem_fun(&cty pe<char>::tolow er), ct));

I couldn't get it to compile, but dig in that direction.

Well i don't have a member function.

If you didn't, why were you trying to say

ct.tolower

? Isn't the notation '.' meant for member access? I must
be missing something here...

V