MISRA.FOR.INCR

For loop increment expression does not have a standard form - increment/decrement by constant step.

MISRA-C++ Rule 6-5-4 (required): The loop-counter shall be modified by one of: --, ++, -=n, or +=n; where n remains constant for the duration of the loop.

Rationale

This helps to ensure deterministic loop termination. The other for loop rules mean that the modification can only take place within expression.

Example

for ( x = 0; x < 10; ++x )         // Compliant
for ( T x = thing.start( );
   x != thing.end( );
   ++x ) // Compliant
for ( x = 0; x < 10; x += 1 )      // Compliant
for ( x = 0; x < 10; x += n )      // Compliant if n is not modified
                                   // within the body of the loop.
for ( x = 0; x < 10; x += fn ( ) ) // Non-compliant