https://github.com/ClickHouse/ClickHouse/blob/9a48cf0da8badfc5f3da08611eb44961aa28e3f6/src/Functions/FunctionsHashing.h#L669-L671

There's a call to `blake3_free_char_pointer` that passes ownership of the pointer back to Rust (which then frees the memory), then there's a call to `std::string`'s constructor that accepts that now-freed pointer.
struct ImplWyHash64
{
    static constexpr auto name = "wyHash64";
    using ReturnType = UInt64;
    static UInt64 apply(const char * s, const size_t len)
    {
        return wyhash(s, len, 0, _wyp);
    }
    static UInt64 combineHashes(UInt64 h1, UInt64 h2)
    {
        union
        {
            UInt64 u64[2];
            char chars[16];
        };
        u64[0] = h1;
        u64[1] = h2;
        return apply(chars, 16);
    }
    static constexpr bool use_int_hash_for_pods = false;
};
struct NameIntHash32 { static constexpr auto name = "intHash32"; };
struct NameIntHash64 { static constexpr auto name = "intHash64"; };
using FunctionSipHash64 = FunctionAnyHash<SipHash64Impl>;
using FunctionIntHash32 = FunctionIntHash<IntHash32Impl, NameIntHash32>;
using FunctionIntHash64 = FunctionIntHash<IntHash64Impl, NameIntHash64>;
#if USE_SSL
using FunctionMD4 = FunctionStringHashFixedString<MD4Impl>;
using FunctionHalfMD5 = FunctionAnyHash<HalfMD5Impl>;
using FunctionMD5 = FunctionStringHashFixedString<MD5Impl>;