Essential rank of variabls and constants

[misra-c]

The following examples assumes the following type ranges:

• char - 8 bits
  short - 16 bits
  int - 32 bits
  long - 64 bits

and that the constants are written in decimal form with no suffices.

Code:

| Constant value range                     | Essential Type
| -2**7 .. 2**7-1                          | essentially signed char  |
| -2**15 .. -2**7-1  and  2**7 .. 2**15-1  | essentially signed short |
| -2**31 .. -2**15-1 and 2**15 .. 2**31-1  | essentially signed int   |
| -2**63 .. -2**31-1 and 2**31 .. 2**63-1  | essentially signed long  |

So for example 2147483647 (2**31-1) will have an essential type of essentially signed int, but 2147483648 (2**31) will have an essential type of essentially signed long.

2**X is used to represent 2 to the power X