Subclause 6.7.6.5.3 [basic.stc.dynamic.deallocation] paragraph 3 specifies:

Each deallocation function shall return void. ...

It has caused confusion in the marketplace whether that is a syntactic constraint on the return type of a deallocation function, or a semantic constraint on the behavior (e.g. a deallocation cannot perform a longjmp).

Possible resolution:

Change in 6.7.6.5.3 [basic.stc.dynamic.deallocation] paragraph 3 as follows:

Each A deallocation function shall have a declared return type of type void. ...