#include <vector>
#include <string>
int main()
{
    // This crashes (expectedly)
    //std::vector<int> vec;
    //vec.reserve(100);
    //vec.data()[50] = 1;
    // This does not crash (it should crash, like `vector`)
    std::basic_string<char> myString;
    myString.reserve(100);
    char* data = &myString[0];
    data[50] = 'A';
}

    constexpr void reserve(_CRT_GUARDOVERFLOW const size_type _Newcap) {
        // [... removed stuff]
        const size_type _Old_size = _Mypair._Myval2._Mysize;
        _Reallocate_grow_by(_Newcap - _Old_size,
            [](_Elem* const _New_ptr, const _Elem* const _Old_ptr, const size_type _Old_size)
                _STATIC_CALL_OPERATOR { _Traits::copy(_New_ptr, _Old_ptr, _Old_size + 1); });
        _Mypair._Myval2._Mysize = _Old_size;
        // [... removed stuff]

    template <class _Fty, class... _ArgTys>
    _CONSTEXPR20 basic_string& _Reallocate_grow_by(const size_type _Size_increase, _Fty _Fn, _ArgTys... _Args) {
        // reallocate to increase size by _Size_increase elements, new buffer prepared by
        // _Fn(_New_ptr, _Old_ptr, _Old_size, _Args...)
        
        // [... removed stuff]
        const size_type _New_size     = _Old_size + _Size_increase; // << [added: assumes new size is equal to capacity]
        const size_type _Old_capacity = _My_data._Myres;
        size_type _New_capacity       = _Calculate_growth(_New_size);
        auto& _Al                     = _Getal();
        const pointer _New_ptr        = _Allocate_for_capacity(_Al, _New_capacity); // throws
        // [... removed stuff]
        _ASAN_STRING_REMOVE(*this);
        _My_data._Mysize      = _New_size;
        _My_data._Myres       = _New_capacity;
        // [... removed stuff]
        _ASAN_STRING_CREATE(*this); // [added: adjusts ASan with wrong assumption]
        return *this;
    }