Re: [Boost-users] Using Boost string library

19 Feb 2007


      On 2/18/07, Pavol Droba  wrote:
...
Hi,
Meryl Silverburgh wrote:
...
Thanks for your idea.
I have cases like this:
/1/1
/1/2/3/2
Since the first string /1/1 is smaller than the /1/2 (1 is < 2) of the
/1/2/3/2, I should able to stop comparison by looking at the 4th
character (/1/2) of '/1/2/3/2'.
So for cases like that, I would like to stop as soon as i can tell one
string is shorter than the other, instead of splitting the whole
string.
This is exactly what would happen you use the second approach I gave you.
Constructing the iterator_range from the split iterator does not perform
any actual searching, and lexicographical_compare stops on the first
possible index (i.e on the first position where inputs are different).
...
...
You can even throw away the vector, and directly create an
iterator_range from the split_iterator. This way you may spare some
unnecessary tokenization.
typedef split_iteratorstring::const_iterator string_split;
iterator_range r1(
        make_split_iterator(s1, is_any_of("/")), string_split())
iterator_range r2(
        make_split_iterator(s2, is_any_of("/")), string_split())
if(lexicographical_compare(r1, r2, integer_compare))
{
        // s1 is less
}
Regards,
Pavol
Pavol,

Thanks for your help. I am trying your second approach.  But I am
having compilation error in this line:
iterator_range r1(
			make_split_iterator(s1, is_any_of("/")), string_split());
error:
../test.cpp:18: error: no matching function for call to
`boost::algorithm::iterator_range::iterator_range(boost::algorithm::split_iterator<__gnu_cxx::__normal_iterator
...
...
, string_split)'
/usr/include/boost/algorithm/string/iterator_range.hpp:89: note:
candidates are:
boost::algorithm::iterator_range<IteratorT>::iterator_range(const
boost::algorithm::iterator_range<IteratorT>&) [with IteratorT =
string_split]
/usr/include/boost/algorithm/string/iterator_range.hpp:85: note:
Complete program:
#include <iostream>
#include <string>

#include "boost/algorithm/string/find_iterator.hpp"
#include "boost/algorithm/string/classification.hpp"
using namespace std;
using namespace boost::algorithm;

typedef split_iteratorstring::const_iterator string_split;

int main(int argc, char **argv) {
	cout << "hello world" << endl;
	
	string s1("/1/1/2");
	string s2("/1/1/3");
	
	iterator_range r1(
			make_split_iterator(s1, is_any_of("/")), string_split());

		iterator_range r2(
			make_split_iterator(s2, is_any_of("/")), string_split());

		if(lexicographical_compare(r1, r2, integer_compare))
		{
			cout << " s1 is less " << endl;
		} else {
			cout << " s2 is less " << endl;
		}
		}
	
}

complete error:

**** Build of configuration Debug for project str ****

make -k all
Building file: ../test.cpp
Invoking: GCC C++ Compiler
g++ -O0 -g3 -Wall -c -fmessage-length=0 -MMD -MP -MF"test.d"
-MT"test.d" -o"test.o" "../test.cpp"
../test.cpp: In function `int main(int, char**)':
../test.cpp:18: error: no matching function for call to
`boost::algorithm::iterator_range::iterator_range(boost::algorithm::split_iterator<__gnu_cxx::__normal_iterator
...
...
, string_split)'
/usr/include/boost/algorithm/string/iterator_range.hpp:89: note:
candidates are:
boost::algorithm::iterator_range<IteratorT>::iterator_range(const
boost::algorithm::iterator_range<IteratorT>&) [with IteratorT =
string_split]
/usr/include/boost/algorithm/string/iterator_range.hpp:85: note:
          boost::algorithm::iterator_range<IteratorT>::iterator_range(const
std::pair<_ForwardIterator, _ForwardIterator>&) [with IteratorT =
string_split]
/usr/include/boost/algorithm/string/iterator_range.hpp:81: note:
          boost::algorithm::iterator_range<IteratorT>::iterator_range(IteratorT,
IteratorT) [with IteratorT = string_split]
/usr/include/boost/algorithm/string/iterator_range.hpp:77: note:
          boost::algorithm::iterator_range<IteratorT>::iterator_range()
[with IteratorT = string_split]
../test.cpp:21: error: no matching function for call to
`boost::algorithm::iterator_range::iterator_range(boost::algorithm::split_iterator<__gnu_cxx::__normal_iterator
, string_split)'
/usr/include/boost/algorithm/string/iterator_range.hpp:89: note:
candidates are:
boost::algorithm::iterator_range<IteratorT>::iterator_range(const
boost::algorithm::iterator_range<IteratorT>&) [with IteratorT =
string_split]
/usr/include/boost/algorithm/string/iterator_range.hpp:85: note:
          boost::algorithm::iterator_range<IteratorT>::iterator_range(const
std::pair<_ForwardIterator, _ForwardIterator>&) [with IteratorT =
string_split]
/usr/include/boost/algorithm/string/iterator_range.hpp:81: note:
          boost::algorithm::iterator_range<IteratorT>::iterator_range(IteratorT,
IteratorT) [with IteratorT = string_split]
/usr/include/boost/algorithm/string/iterator_range.hpp:77: note:
          boost::algorithm::iterator_range<IteratorT>::iterator_range()
[with IteratorT = string_split]
../test.cpp:23: error: `integer_compare' was not declared in this scope
../test.cpp:23: warning: unused variable 'integer_compare'
../test.cpp: At global scope:
../test.cpp:31: error: expected declaration before '}' token
/usr/include/boost/function/function_template.hpp: In static member
function `static R
boost::detail::function::function_obj_invoker2::invoke(boost::detail::function::any_pointer, T0, T1) [with
FunctionObj = boost::algorithm::detail::is_any_ofF<char>, R =
boost::algorithm::iterator_range<__gnu_cxx::__normal_iterator
, T0 = __gnu_cxx::__normal_iterator >, T1 =
__gnu_cxx::__normal_iterator >]':
/usr/include/boost/function/function_template.hpp:482:   instantiated
from `void boost::function2::assign_to(FunctionObj,
boost::detail::function::function_obj_tag) [with FunctionObj =
boost::algorithm::detail::is_any_ofF<char>, R =
boost::algorithm::iterator_range<__gnu_cxx::__normal_iterator
, T0 = __gnu_cxx::__normal_iterator >, T1 =
__gnu_cxx::__normal_iterator >, Allocator =
std::allocatorboost::function_base]'
/usr/include/boost/function/function_template.hpp:433:   instantiated
from `void boost::function2::assign_to(Functor)
[with Functor = boost::algorithm::detail::is_any_ofF<char>, R =
boost::algorithm::iterator_range<__gnu_cxx::__normal_iterator
, T0 = __gnu_cxx::__normal_iterator >, T1 =
__gnu_cxx::__normal_iterator >, Allocator =
std::allocatorboost::function_base]'
/usr/include/boost/function/function_template.hpp:289:   instantiated
from `boost::function2::function2(Functor,
typename boost::enable_if_c< boost::type_traits::ice_not<
boost::is_integral<Functor>::value>::value, int>::type) [with Functor
= boost::algorithm::detail::is_any_ofF<char>, R =
boost::algorithm::iterator_range<__gnu_cxx::__normal_iterator
, T0 = __gnu_cxx::__normal_iterator >, T1 =
__gnu_cxx::__normal_iterator >, Allocator =
std::allocatorboost::function_base]'
/usr/include/boost/algorithm/string/detail/find_iterator.hpp:50:
instantiated from
`boost::algorithm::detail::find_iterator_base<IteratorT>::find_iterator_base(FinderT,
int) [with FinderT = boost::algorithm::detail::is_any_ofF<char>,
IteratorT = __gnu_cxx::__normal_iterator
]'
/usr/include/boost/algorithm/string/find_iterator.hpp:262:
instantiated from
`boost::algorithm::split_iterator<IteratorT>::split_iterator(IteratorT,
IteratorT, FinderT) [with FinderT =
boost::algorithm::detail::is_any_ofF<char>, IteratorT =
__gnu_cxx::__normal_iterator >]'
/usr/include/boost/algorithm/string/find_iterator.hpp:351:
instantiated from `boost::algorithm::split_iterator
boost::algorithm::make_split_iterator(CollectionT&, FinderT) [with
CollectionT = std::string, FinderT =
boost::algorithm::detail::is_any_ofF<char>]'
../test.cpp:18:   instantiated from here
/usr/include/boost/function/function_template.hpp:111: error: no match
for call to `(boost::algorithm::detail::is_any_ofF<char>)
(__gnu_cxx::__normal_iterator >&,
__gnu_cxx::__normal_iterator >&)'
make: *** [test.o] Error 1
make: Target `all' not remade because of errors.
Build complete for project str
...
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