C / C++ / MFC

klutez123 wrote:

// The following loop gets the high temperatures from the user for as
// many days as the user specified in num_values.
for(index = 0; index <= (num_values - 1); index++)
{
cout << "Enter the high temperature for day " << index + 1 << ": ";
cin >> daily_temp[index]; // input value into array
}

int low = 500;
int high = -500;
 
for (index = 0; index <= (num_values - 1); index++)
{
    cout << "Enter the high temperature for day " << index + 1 << ": ";
    cin >> daily_temp[index];
 
    if (daily_temp[index] > high)
        high = daily_temp[index];
    else if (daily_temp[index] < low)
        low = daily_temp[index];
}

anumadhu wrote:

myServiceMain(int arg, char *argv)
{
hStatus=RegisterServiceCtrlHandler(szServiceName, handlerFunc);
SetServiceStatus(hStatus, &ServiceStatus);

mo_nica881 wrote:

what is the role of #pragma pack(1).

mo_nica881 wrote:

in some program i always see "#pragma pack(1)" included in Header. what is the role of #pragma pack(1).

struct aligntest
{
    char aChar;
    int nNum;
};

#pragma pack( push, 1 ) // Set alignment to 1
struct IntParts
{
   BYTE byPart1;
   BYTE byPart2;
   BYTE byPart3;
   BYTE byPart4;
};
#pragma pack( pop ) // Restore previous settings

int nSplit = 123213;
IntPart ip = { 0 };
memcpy( &ip, &nSplit, sizeof( ip ));

Nibu babu thomas wrote:

Normally sizeof( aligntest ) will return 8 but the actual size is 5. Extra 3 bytes is used for padding. This is done for efficiency sake.

#pragma pack( push, 1 ) // Set alignment to 1
struct IntParts
{
   BYTE byPart1;
   BYTE byPart2;
   BYTE byPart3;
   BYTE byPart4;
};
#pragma pack( pop ) // Restore previous settings

int nSplit = 123213;
IntPart ip = { 0 };
memcpy( &ip, &nSplit, sizeof( ip ));

sk8er_boy287 wrote:

I'm pretty much sure (from experience) that sizeof always returns the size of the type of structure (5 for your code sample). sizeof doesn't care about memory alignment.