Recently, it was really difficult for me to find out what happens when you transparently replace a subobject. [basic.life] p9 does not elaborate on this; the relevant parts are in [intro.object] p2.

Namely, the containing object is kept alive if the conditions are met and can be used to access the new subobject. A new note highlights this behavior and links back to [intro.object].

Furthermore, [basic.life] Example 3 is currently ill-formed (fixed by this PR) because it contains c1 = c2; at a top level, which should be taking place in a function body. The example is further expanded by two lines that demonstrate how a containing object survives when transparent replacement of one of its subobjects takes place.