inline CPLSafeInt<int> operator+( const CPLSafeInt<int>& A,
const CPLSafeInt<int>& B )
{
#ifdef BUILTIN_OVERFLOW_CHECK_AVAILABLE
int res;
if( __builtin_sadd_overflow(A.v(), B.v(), &res) )
throw CPLSafeIntOverflow();
return CPLSM(res);
#elif defined(_MSC_VER)
msl::utilities::SafeInt<int, CPLMSVCSafeIntException> A2(A.v());
msl::utilities::SafeInt<int, CPLMSVCSafeIntException> B2(B.v());
return CPLSM(static_cast<int>(A2 + B2));
#elif defined(CPL_HAS_GINT64)
const int a = A.v();
const int b = B.v();
const GInt64 res = static_cast<GInt64>(a) + b;
if( res < std::numeric_limits<int>::min() ||
res > std::numeric_limits<int>::max() )
{
throw CPLSafeIntOverflow();
}
return CPLSM(static_cast<int>(res));
#else
return SafeAddSigned(A,B);
#endif
}
/*
https://codereview.stackexchange.com/questions/37177/simpler-method-to-detect-int-overflow
*/
int safe_add(int32_t a, int32_t b, int * error) {
int32_t result;
int overflow = __builtin_sadd_overflow(a, b, &result);
if (overflow){
*error = overflow;
}
return result;
}
constexpr Result<int> sadd(int lhs, int rhs) {
int sum{};
return {__builtin_sadd_overflow(lhs, rhs, &sum), sum};
}
int
foo (int x, int y)
{
int r;
return __builtin_sadd_overflow (x, y, &r);
}