Закралось, тут у меня сомнения относительно производительности операций создания и заполнения векторов, решил провестий простой тест, код ниже. Результаты несколько меня удивили:
В Debug-mode:

The above code block-1 was executed in 0.0500 second(s)
The above code block-2 was executed in 44.5400 second(s)

В Realese-mode:

The above code block-1 was executed in 0.0440 second(s)
The above code block-2 was executed in 0.1030 second(s)

Каждый тест запускался по 10 раз, отображены средние результаты.

#include <windows.h>
#include <time.h>
#include <iostream>
#include <vector>
 
HANDLE gHeap;
 
int _tmain(int argc, _TCHAR* argv[])
{
	gHeap = HeapCreate(0,6553,65530);
	int test[1000]={0};
 
	clock_t start = clock();
	for (int i=0;i<100000;i++){
		int* var1 = (int*)HeapAlloc(gHeap,0,1000);
		memcpy(var1, &test[0], 1000);
 
		int* var2 = (int*)HeapAlloc(gHeap,0,900);
		memcpy(var2, &var1[99], 900);
		HeapFree(gHeap,0,var1);
 
		memcpy(&test[99], var2, 900);
		HeapFree(gHeap,0,var2);
	}
	clock_t stop = clock();
	printf("The above code block-1 was executed in %.4f second(s)n", ((double) stop - start) / ((double) CLOCKS_PER_SEC));
 
 
	start = clock();
	for (int i=0;i<100000;i++){
		std::vector<int> var3(1000);
		memcpy(&var3[0], &test[0], 1000);
 
		std::vector<int> var4(var3);
		memcpy(&test[99], &var4[99], 900);
	}
	stop = clock();
	printf("The above code block-2 was executed in %.4f second(s)n", ((double) stop - start) / ((double) CLOCKS_PER_SEC));
 
	HeapDestroy(gHeap);
 
	//getchar();
	return 0;
}