std::copy对std::vector、std::set、数组的使用_std::vector copy

注意：std::copy只负责复制，不负责申请空间，所以复制前必须有足够的空间！！！

std::copy的函数形式为：

std::copy(src_start_iter, src_end_iter, std::back_inserter(dst_container));

以下为写的测试代码：

#include <iostream>
#include <string>
#include <algorithm>
#include <vector>
#include <set>
#include <map>
 
void stdCopyTest()
{
	// vector copy to vector
	{
		std::vector<int> vtSrc = { 1, 2, 3, 4, 5 };
		std::vector<int> vtDst(6, 0); // std::vector(size, init_data), insert into begin，it must be new enough space first.
		std::copy(vtSrc.begin(), vtSrc.end(), vtDst.begin());
		for (size_t i = 0, uSize = vtDst.size(); i < uSize; ++i)
		{
			std::cout << vtDst[i] << '\t';
		}
		std::cout << std::endl;
 
		std::vector<int> vtDst01(0);
		std::copy(vtSrc.begin(), vtSrc.end(), std::back_inserter(vtDst01));
		for (size_t i = 0, uSize = vtDst01.size(); i < uSize; ++i)
		{
			std::cout << vtDst01[i] << '\t';
		}
		std::cout << std::endl;
	}
 
	// set insert into vector
	{
		std::set<int> setSrc = { 5, 4, 3, 2, 1 };
		std::vector<int> vtDst;
		std::copy(setSrc.begin(), setSrc.end(), std::back_inserter(vtDst));
		for (size_t i = 0, uSize = vtDst.size(); i < uSize; ++i)
		{
			std::cout << vtDst[i] << '\t';
		}
		std::cout << std::endl;
	}
 
	// array insert into vector
	{
		int szSrc[5] = { 1, 2, 3, 4, 5 };
		std::vector<int> vtDst;
		std::copy(szSrc, szSrc + sizeof(szSrc) / sizeof(int), std::back_inserter(vtDst));
		for (size_t i = 0, uSize = vtDst.size(); i < uSize; ++i)
		{
			std::cout << vtDst[i] << '\t';
		}
		std::cout << std::endl;
	}
 
	// vector insert into array
	{
		std::vector<int> vtSrc = { 1, 2, 3, 4, 5 };
		int szDst[8] = { -1 };
		std::copy(vtSrc.begin(), vtSrc.end(), szDst);
		for (size_t i = 0, uSize = vtSrc.size(); i < uSize; ++i)
		{
			std::cout << szDst[i] << '\t';
		}
		std::cout << std::endl;
	}
 
	// array insert into array
	{
		int szSrc[5] = { 1, 2, 3, 4, 5 };
		int szDst[8] = { -1 };
		std::copy(szSrc, szSrc + sizeof(szSrc) / sizeof(int), szDst);
 
		for (size_t i = 0, uSize = sizeof(szSrc) / sizeof(int); i < uSize; ++i)
		{
			std::cout << szDst[i] << '\t';
		}
		std::cout << std::endl;
	}
 
	// map copy to map
	{
		std::map<int, std::string> mp4Src = 
		{
			std::pair<int, std::string>(1, "abc123"),
			std::pair<int, std::string>(2, "bcd456"),
			std::pair<int, std::string>(3, "cde789"),
		};
 
		std::cout << "***********************" << std::endl;
		std::map<int, std::string> mp4Dst;
		mp4Dst.insert(mp4Src.begin(), mp4Src.end());
		for (auto iter = mp4Dst.begin(); iter != mp4Dst.end(); ++iter)
		{
			std::cout << iter->first << ": " << iter->second << std::endl;
		}
		std::cout << "***********************" << std::endl;
	}
 
	return;
}