A static assert is the main language feature for implementing custom compile-time checks. It can check any condition. If the static assert is compiled, the condition must be true; otherwise, it will issue a compile-time error. Here, we'll use it to verify whether our struct is of the correct size to interface with hardware.

align(1) struct IDTLocation {
  align(1):
  ushort length;
  uint offset;
}
static assert(IDTLocation.sizeof == 6, "An IDTLocation must be exactly six bytes with no padding.");