Adding a bunch of lines like `#pragma GCC poison new` to the last-included header of every source file is very useful. It doesn't fully stop manual memory management from sneaking into headers (since it absolutely will break system headers, though maybe if modules work that would be avoided).

For the rare case of porting software with unclear ownership, I use a `dumb_ptr` template with allocation and deallocation methods. Since this is header-only it naturally avoids the poisoning.

In particular, the `vector` method mentioned elsewhere is completely broken since objects move and thus you can't keep weak/borrowed references to them. If you use indices you give up on all ownership and are probably using global variables, ick. Please just write a proper pool allocator if that's what you want (possibly using generational references to implement weak).