Processors do not access memory one byte at a time, but in larger chunks of powers of twos (2, 4, 8, 16, 32, and so on). Owing to this, it is important that compilers align data in memory so that it can be easily accessed by the processor. Should this data be misaligned, the compiler has to do extra work for accessing data; it has to read multiple chunks of data, shift, and discard unnecessary bytes and combine the rest together.
C++ compilers align variables based on the size of their data type: 1 byte for bool and char, 2 bytes for short, 4 bytes for int, long and float, 8 bytes for double and long long, and so on. When it comes to structures or unions, the alignment must match the size of the largest member in order to ...
