On Sat, May 08, 2004 at 10:07:30PM +1000, Thorsten Ottosen wrote:
| > Pavol uses it havily in his string library. The "dangerous" thing would be not to put | > computation of the end-iterator out-side the loop, eg. | > | > for( iterator_type_of<T>::type i = begin( c ); i != end( c ); ... ) | > ^^^^^^^^^^ ^ | > is not good. But one wouldn't do that anyway. And if one did it, what are the chances of | > the argument being a char*? | | Too many chances are being taken here, IMO.
the more chances that are taken, the less the likelihood of it all happening.
| It doesn't feel right. | STL's end is guaranteed O(1) and I'm really concerned about anything | that violates that expectation.
ok. I have forgotte why Pavol want to support char* at all. I mean, programming with manual insertion of null is really error-prone. If char* is considered a range, one might even say
std::string s; my_algo( s.buffer() ); // oops, no terminating null!
There is a lot of legacy code out there with no counterpart in c++. I don't think, that we can afford not to support it. Just have a look at the Boost Regex interface. char* is still there, and there are reasons for it. An implication of supporting char* is the requirement, that char[] must be threated the same way. If you consider the way how std::string's end() works you have the current specification of the collection traits for string. An example of usecase for all string variants: #include <iostream> #include <string> #include <boost/algorithm/string.hpp> using namespace std; using namespace boost; int main(int argc, char* argv[]) { // check if the first argument contains "hello" // char* is used for input char[] for search specifier iterator_range<char*> r=find_first(argv[0], "hello"); if( !r.empty() ) { // convert the find result (a pair of char*) to std::string string str(r.begin(), r.end()); str+=" "; str+=str; cout << str << endl; } return 0; } An example may not be very usable, but it shows a common pattern, when char*, char[], and std::string are used in one place. Regards, Pavol