sizeof() returns "wrong" Size of structure

[Mkz]

Just to make sure you know the *reason*:

After "m_uImageType" and before "m_sColorMapStart", the compiler inserted a padding "0", so that the 2-byte-wide "m_sColorMapStart" will be stored at an address which is a multiple of 2. If you had a DWORD, the compiler would pad with zeroes until the address would be a multiple of 4, and so on.

The pragma directive will tell the compiler not to bother aligning the structures.

If you follow the address of each structure member and add the length of the padding zeroes where they are "needed", you'll see that the total length is 20.