有关" Use After Free"的问题

C++学艺不精看不懂这个错，请各位大佬帮忙看一下这里为什么会报一个Use After Free啊。

Result<pcrepp, pcrepp::compile_error> pcrepp::from_str(std::string pattern, int options)
{
    const char *errptr;
    int eoff;
    auto code = pcre_compile(pattern.c_str(),
                             options | PCRE_UTF8,
                             &errptr,
                             &eoff,
                             nullptr);

    if (!code) {
        return Err(compile_error{errptr, eoff});
    }

    return Ok(pcrepp(std::move(pattern), code));//这一行报错
}
//报错信息
//call to `Result` eventually accesses memory that was invalidated by call to `free()` on line 86 indirectly during the call to `Ok`.
//84.     }
//85. 
//86.     return Ok(pcrepp(std::move(pattern), code));
//        ^
//87. }
//88.

Ok方法

template<typename T, typename CleanT = typename std::decay<T>::type>
types::Ok<CleanT> Ok(T&& val) {
    return types::Ok<CleanT>(std::forward<T>(val));
}

Result的构造函数

    Result(types::Ok<T> ok)
        : ok_(true)
    {
        storage_.construct(std::move(ok));
    }

谢谢各位大佬了[抱拳]