std::copy() std::back_inserter()

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std::copy

template<class InputIterator, class OutputIterator>OutputIterator copy (InputIterator first, InputIterator last, OutputIterator result)
{while (first!=last) {*result = *first;++result; ++first;}
  return result;
}

std::copy()函数和strcpy()的实现类似,只是参数类型由char 变为 iterator

// copy algorithm example
#include <iostream>     // std::cout
#include <algorithm>    // std::copy
#include <vector>       // std::vectorint main () {int myints[]={10,20,30,40,50,60,70};std::vector<int> myvector (7);//一定要初始化大小//这三个参数要记住std::copy ( myints, myints+7, myvector.begin() );//参数       first   last      result    // [first,last)std::cout << "myvector contains:";for (std::vector<int>::iterator it = myvector.begin(); it!=myvector.end(); ++it)std::cout << ' ' << *it;std::cout << '\n';return 0;
}

Output:
myvector contains: 10 20 30 40 50 60 70

std::back_inserter()

// back_inserter example
#include <iostream>     // std::cout
#include <iterator>     // std::back_inserter
#include <vector>       // std::vector
#include <algorithm>    // std::copyint main () {std::vector<int> foo,bar;for (int i=1; i<=5; i++){ foo.push_back(i); bar.push_back(i*10); }std::copy (bar.begin(),bar.end(),back_inserter(foo));
//back_inserter() 把当前iterator插入到foo容器尾部，返回类型是一个叫back_insert_iterator的东西..std::cout << "foo contains:";for ( std::vector<int>::iterator it = foo.begin(); it!= foo.end(); ++it )std::cout << ' ' << *it;std::cout << '\n';return 0;
}

Output:foo contains: 1 2 3 4 5 10 20 30 40 50

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