Function hash_pair

src/fl/stl/hash.h:91–96

3) Handy two-word hasher

// 3) Handy two-word hasher
static inline u32 hash_pair(u32 a, u32 b,
                                 u32 seed = 0) FL_NOEXCEPT {
    // mix in 'a', then mix in 'b'
    u32 h = fast_hash32(seed ^ a);
    return fast_hash32(h ^ b);
}

static inline u32 fast_hash64(u64 x) FL_NOEXCEPT {
    u32 x1 = static_cast<u32>(x & 0x00000000FFFFFFFF);