Mega Code Archive
Create back_insert_iterator
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/* The following code example is taken from the book
* "The C++ Standard Library - A Tutorial and Reference"
* by Nicolai M. Josuttis, Addison-Wesley, 1999
*
* (C) Copyright Nicolai M. Josuttis 1999.
* Permission to copy, use, modify, sell and distribute this software
* is granted provided this copyright notice appears in all copies.
* This software is provided "as is" without express or implied
* warranty, and with no claim as to its suitability for any purpose.
*/
#include <iostream>
#include <vector>
#include <algorithm>
/* PRINT_ELEMENTS()
* - prints optional C-string optcstr followed by
* - all elements of the collection coll
* - separated by spaces
*/
template <class T>
inline void PRINT_ELEMENTS (const T& coll, const char* optcstr="")
{
typename T::const_iterator pos;
std::cout << optcstr;
for (pos=coll.begin(); pos!=coll.end(); ++pos) {
std::cout << *pos << ' ';
}
std::cout << std::endl;
}
using namespace std;
int main()
{
vector<int> coll;
// create back inserter for coll
// - inconvenient way
back_insert_iterator<vector<int> > iter(coll);
// insert elements with the usual iterator interface
*iter = 1;
iter++;
*iter = 2;
iter++;
*iter = 3;
PRINT_ELEMENTS(coll);
// create back inserter and insert elements
// - convenient way
back_inserter(coll) = 44;
back_inserter(coll) = 55;
PRINT_ELEMENTS(coll);
// use back inserter to append all elements again
// - reserve enough memory to avoid reallocation
coll.reserve(2*coll.size());
copy (coll.begin(), coll.end(), // source
back_inserter(coll)); // destination
PRINT_ELEMENTS(coll);
}
1 2 3
1 2 3 44 55
1 2 3 44 55 1 2 3 44 55
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