inline CPLSafeInt<int> operator-( const CPLSafeInt<int>& A, const CPLSafeInt<int>& B ) { #ifdef BUILTIN_OVERFLOW_CHECK_AVAILABLE int res; if( __builtin_ssub_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 SafeSubSigned(A,B); #endif }
constexpr Result<int> ssub(int lhs, int rhs) { int sum{}; return {__builtin_ssub_overflow(lhs, rhs, &sum), sum}; }