https://github.com/bitcoin/bitcoin/blob/68f3c7eb080e461cfeac37f8db7034fe507241d0/src/prevector.h#L152-L158

I'm opening an issue as its fix is too tiny to become a pull request.

Can be solved by renaming the struct to
```c
     struct indirect_contents { 
         size_type capacity; 
         char* indirect; 
     }; 
```
const T* item_ptr(difference_type pos) const { return is_direct() ? direct_ptr(pos) : indirect_ptr(pos); }
    void fill(T* dst, ptrdiff_t count, const T& value = T{}) {
        std::fill_n(dst, count, value);
    }
    template<typename InputIterator>
    void fill(T* dst, InputIterator first, InputIterator last) {