Comment by gavinray

I want to point out an implemented feature that people SHOULD be adopting but that I doubt will be picked up:

  P2590R2, Explicit lifetime management (PR106658)

This is for "std::start_lifetime_as<T>". If you have not heard of this before, it's the non-UB way to type-pun a pointer into a structured type.

Nearly all zero-copy code that deals with external I/O buffers looks something like:

  std::unique_ptr<char[]> buffer = stream->read();
  if (buffer[0] == FOO)
    processFoo(reinterpret_cast<Foo*>(buffer.get())); // undefined behavior
  else
    processBar(reinterpret_cast<Bar*>(buffer.get())); // undefined behaviour

With this merged, swap the reinterpret_cast for start_lifetime_as and you're no longer being naughty.

https://en.cppreference.com/cpp/memory/start_lifetime_as