Problem with counting iterator and bind
I have this: typedef LegacySequentialContainer<string> LegacyStringVector; LegacyStringVector lsv; // ... filling lsv with strings ... I realized this: boost::counting_iterator<int> it(0); boost::counting_iterator<int> end(lsv.length()); while (it < end) cout << boost::bind(&LegacyStringVector::operator[], v3, _1)(*it++) << " "; cout << "\n"; and it works. However, I wish to do the same but using std::copy or std::for_each instead. I tried the following but none is able to compile: copy(boost::counting_iterator<int>(0), boost::counting_iterator<int>(v3.size()), boost::bind(ostream_iterator<string>(cout, " "), &vector<string>::operator[], v3, _1)); copy(boost::counting_iterator<int>(0), boost::counting_iterator<int>(v3.size()), boost::bind(ostream_iterator<string>(cout, " "), boost::bind<string,int>(&vector<string>::operator[], v3, _1))); copy(boost::counting_iterator<int>(0), boost::counting_iterator<int>(v3.size()), boost::bind(ostream_iterator<string>(cout, " "), boost::bind<string,int>(&vector<string>::operator[], v3), _1)); I must be close to the solution but error messages do not help guiding me in the right direction. Anyone has any suggestion?
Maitre Bart <maitrebart <at> excite.com> writes: Typos corrected: I have this: typedef LegacySequentialContainer<string> LegacyStringVector; LegacyStringVector lsv; // ... filling lsv with strings ... I realized this: boost::counting_iterator<int> it(0); boost::counting_iterator<int> end(lsv.length()); while (it < end) cout << boost::bind(&LegacyStringVector::operator[], lsv, _1)(*it++) << " "; cout << "\n"; and it works. However, I wish to do the same but using std::copy or std::for_each instead. I tried the following but none is able to compile: copy(boost::counting_iterator<int>(0), boost::counting_iterator<int>(lsv.size()), boost::bind(ostream_iterator<string>(cout, " "), &vector<string>::operator[], lsv, _1)); copy(boost::counting_iterator<int>(0), boost::counting_iterator<int>(lsv.size()), boost::bind(ostream_iterator<string>(cout, " "), boost::bind<string,int>(&vector<string>::operator[], lsv, _1))); copy(boost::counting_iterator<int>(0), boost::counting_iterator<int>(lsv.size()), boost::bind(ostream_iterator<string>(cout, " "), boost::bind<string,int>(&vector<string>::operator[], lsv), _1)); I must be close to the solution but error messages do not help guiding me in the right direction. Anyone has any suggestion?
Maitre Bart wrote:
Maitre Bart <maitrebart <at> excite.com> writes:
Typos corrected:
I have this:
typedef LegacySequentialContainer<string> LegacyStringVector;
LegacyStringVector lsv;
// ... filling lsv with strings ...
I realized this:
boost::counting_iterator<int> it(0); boost::counting_iterator<int> end(lsv.length()); while (it < end) cout << boost::bind(&LegacyStringVector::operator[], lsv, _1)(*it++) << " "; cout << "\n";
and it works. However, I wish to do the same but using std::copy or std::for_each instead.
I tried the following but none is able to compile:
copy(boost::counting_iterator<int>(0), boost::counting_iterator<int>(lsv.size()), boost::bind(ostream_iterator<string>(cout, " "), &vector<string>::operator[], lsv, _1));
std::copy doesn't take a function object as it third argument, just an iterator. Try std::transform: std::transform( boost::counting_iterator<int>(0), boost::counting_iterator<int>(lsv.size()), ostream_iterator<string>(cout, " "), boost::bind( &LegacyStringVector::operator[], lsv, _1) );
Peter Dimov wrote:
std::transform( boost::counting_iterator<int>(0), boost::counting_iterator<int>(lsv.size()), ostream_iterator<string>(cout, " "), boost::bind( &LegacyStringVector::operator[], lsv, _1)
Make that boost::bind( &LegacyStringVector::operator[], &lsv, _1) or boost::bind( &LegacyStringVector::operator[], boost::cref(lsv), _1) to not copy the whole lsv.
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Maitre Bart -
Peter Dimov