chunkedseq
container library for large in-memory data sets
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chunkedseq_6.cpp
#include <iostream>
#include <string>
#include <assert.h>
#include "chunkedseq.hpp"
template <class Chunkedseq>
void pcopy(typename Chunkedseq::iterator first,
typename Chunkedseq::iterator last,
Chunkedseq& destination) {
using iterator = typename Chunkedseq::iterator;
using ptr = typename Chunkedseq::const_pointer;
const long cutoff = 8192;
long sz = last.size() - first.size();
if (sz <= cutoff) {
// compute result in a sequential fashion
Chunkedseq::for_each_segment(first, last, [&] (ptr lo, ptr hi) {
destination.pushn_back(lo, hi-lo);
});
} else {
// select split position to be the median
iterator mid = first + (sz/2);
Chunkedseq destination2;
// recurse on subproblems
// calls can execute in parallel
pcopy(first, mid, destination);
pcopy(mid, last, destination2);
// combine results
destination.concat(destination2);
}
}
int main(int argc, const char * argv[]) {
const int chunk_size = 2;
mydeque_type mydeque = { 0, 1, 2, 3, 4, 5 };
mydeque_type mydeque2;
pcopy(mydeque.begin(), mydeque.end(), mydeque2);
std::cout << "mydeque2 contains:";
auto p = mydeque2.begin();
while (p != mydeque2.end())
std::cout << " " << *p++;
std::cout << std::endl;
return 0;
}
//! [pcopy_example]