MISRA.CONV.INT.SIGN

Implicit integral conversion changes signedness.

MISRA-C++ Rule 5-0-4 (required): An implicit integral conversion shall not change the signedness of the underlying type.

Rationale

Some signed to unsigned conversions may lead to implementation-defined behaviour. This behaviour may not be consistent with developer expectations.

Example

void f()
{
   int8_t s8;
   uint8_t u8;
   s8 = u8;                                   // Non-compliant
   u8 = s8 + u8;                              // Non-compliant
   u8 = static_cast< uint8_t > ( s8 ) + u8;   // Compliant
}