IDL provides four sizes of signed and unsigned integer data types, specified as follows:
int_size [int]
unsigned int_size [int]
int_size unsigned [int]
The int_size can take the following values:
hyper
long
short
small
The hyper types are represented in 64 bits. A long is 32 bits. A short is 16 bits. A small is 8 bits.
The keyword int is optional and has no effect. The keyword unsigned denotes an unsigned integer type; it can occur either before or after the size keyword.