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.
static void apply(const char * begin, const size_t size, unsigned char * out_char_data)
    {
        MD4_CTX ctx;
        MD4_Init(&ctx);
        MD4_Update(&ctx, reinterpret_cast<const unsigned char *>(begin), size);
        MD4_Final(out_char_data, &ctx);
    }
};
struct MD5Impl
{
    static constexpr auto name = "MD5";
    enum { length = MD5_DIGEST_LENGTH };
    static void apply(const char * begin, const size_t size, unsigned char * out_char_data)
    {
        MD5_CTX ctx;
        MD5_Init(&ctx);
        MD5_Update(&ctx, reinterpret_cast<const unsigned char *>(begin), size);
        MD5_Final(out_char_data, &ctx);
    }
};
struct SHA1Impl
{
    static constexpr auto name = "SHA1";
    enum { length = SHA_DIGEST_LENGTH };