C++ 的内存获取机制:
void* p1 = malloc(512);
free(p1);
complex<int>* p2 = new complex<int>;
delete p2;
void* p3 = ::operator new(512);
::operator delete(p3);
//GNUC
void* p4 = alloc::allocate(512);
alloc::deallocate(p4, 512);
//GNUC4.9
void* p5 = allocator<int>().allocate(7); //分配7个int
allocator<int>().deallocate((int*)p5, 7);