Function CommutativeMultCheck

tests/SelfTest/IntrospectiveTests/Integer.tests.cpp:15–23

namespace {
    template <typename Int>
    static void
    CommutativeMultCheck( Int a, Int b, Int upper_result, Int lower_result ) {
        using Catch::Detail::extendedMult;
        using Catch::Detail::ExtendedMultResult;
        CHECK( extendedMult( a, b ) ==
               ExtendedMultResult<Int>{ upper_result, lower_result } );
        CHECK( extendedMult( b, a ) ==
               ExtendedMultResult<Int>{ upper_result, lower_result } );
    }

    // Simple (and slow) implementation of extended multiplication for tests
    constexpr Catch::Detail::ExtendedMultResult<std::uint64_t>