I am trying to align a structure using the directive (#pragma pack).
I need it has 112 bytes in size. (14*8=112 bytes).
However it has 80 bytes only.
How to do it correctly?
#pragma pack (8)
struct Deal
{
long deal_ticket;
long order_ticket;
long position_ticket;
long time;
long type;
long entry;
char symbol[8];
double volume;
double price;
double profit;
double swap;
double commission;
long magic;
long reason;
};
int main()
{
cout << sizeof(Deal) << endl;
}
Thank you so much!!
I need it has 112 bytes in size. (14*8=112 bytes).
long
is only guaranteed to be at least 32 bits which is 4 bytes (assuming 8 bit byte); not 8 bytes.
If you want each integer to be 64 bits, then you can use std::int64_t
instead of long
.
#pragma pack
never increases the size of a class. It only ever decreases the size by removing padding that is otherwise required for alignment.
P.S. #pragma pack
doesn't exist in standard C++ (in fact, no standard pragmas exist in C++). It is a language extension.