Reminds me of a startup I worked for in the 1990s. The C code base was organized into "units" (modules). Each unit allocated/destroyed its own data structures, but used the "ref" unit to return a reference (really, a handle) instead of a pointer. Each module used a "deref" function to convert the handle to a typed pointer for internal use.

ref used many of the tricks described in the above post, including an incrementing counter to catch stale handles.

All pointers were converted to handles in debug and testing builds, but in release builds ref simply returned the pointer as a handle, to avoid the performance penalty. As machines grew faster, there was talk of never turning off ref.

Side win: There was a unit called "xref" (external ref) which converted pointers to stable handles in all builds (debug and release). It was the same code, but not compiled out. External refs were used as network handles in the server's bespoke RPC protocol.