Rule Definition
A possible programming error in C++ is to apply the sizeof operator to expression and expect the expression to be evaluated. However, the expression is not evaluated as sizeof only acts on the type of the expression. To avoid this error, sizeof shall not be used on expressions that would contain side effects if they were used elsewhere, as the side effects will not occur.

Remediation
Ensure to separate a side effect of an expression from the sizeof method

Violation Code Sample

int32_t i;
int32_t j;

j = sizeof( i = 1234 ); // Non-compliant - j is set to the sizeof the
// type of i which is an int32_t.
// i is not set to 1234.

Fixed Code Sample

int32_t j;
volatile int32_t k;

j = sizeof ( k ); // Compliant by exception.

MISRA C++ 2008, 5-3-4: Evaluation of the operand to the sizeof operator shall not contain side effects.