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.
vec_to[i] = Impl::combineHashes(vec_to[i], hash);
            }
        }
        else
            throw Exception("Illegal column " + column->getName()
                + " of argument of function " + getName(),
                ErrorCodes::ILLEGAL_COLUMN);
    }
    template <typename FromType, bool first>
    void executeBigIntType(const IColumn * column, typename ColumnVector<ToType>::Container & vec_to) const
    {
        using ColVecType = ColumnVectorOrDecimal<FromType>;
        if (const ColVecType * col_from = checkAndGetColumn<ColVecType>(column))
        {
            const typename ColVecType::Container & vec_from = col_from->getData();
            size_t size = vec_from.size();
            for (size_t i = 0; i < size; ++i)
            {
                ToType h = Impl::apply(reinterpret_cast<const char *>(&vec_from[i]), sizeof(vec_from[i]));
                if constexpr (first)
                    vec_to[i] = h;
                else
                    vec_to[i] = Impl::combineHashes(vec_to[i], h);
            }
        }
        else if (auto col_from_const = checkAndGetColumnConst<ColVecType>(column))
        {
            auto value = col_from_const->template getValue<FromType>();
            ToType h = Impl::apply(reinterpret_cast<const char *>(&value), sizeof(value));
            size_t size = vec_to.size();