#include <iostream>
using namespace std;
 
struct some_struct
{
 double m;
};
 
static_assert(sizeof(some_struct) == sizeof(std::int64_t));
static_assert(alignof(some_struct) == alignof(std::int64_t));
 
char buf[] = {
	// some prefix
	0x1, 0x2, 0x3,
	// now struct data
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x08
};
 
int main() {
	some_struct* s = reinterpret_cast<some_struct*>(buf + 3);
	// now let's check alignment
	std::cout << reinterpret_cast<std::uintptr_t>(s) % alignof(some_struct);
	return 0;
}

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