Using an Uninitialized Variable

    explicit ALWAYS_INLINE MatchResult(EncodedMatchResult encoded)
    {
        union u {
            uint64_t encoded;
            struct s {
                size_t start;
                size_t end;
            } split;
        } value;
        value.encoded = encoded;
        start = value.split.start;
        end = value.split.end;
    }