PS (too late for edit so I'm replying to myself): with the above Clang extension you can also define your own phat_ptr_t struct and still associate the length w

PS (too late for edit so I'm replying to myself): with the above Clang extension you can also define your own phat_ptr_t struct and still associate the length with the pointer. Not sure if that's also possible with the Microsoft extension, for instance this is copied from the proposal text: typedef struct { int *__counted_by(count) buf; size_t count; } sized_buf_t;