6 Basics [basic]

6.7 Memory and objects [basic.memobj]

6.7.5 Storage duration [basic.stc] Dynamic storage duration [basic.stc.dynamic] Deallocation functions [basic.stc.dynamic.deallocation]

Deallocation functions shall be class member functions or global functions; a program is ill-formed if deallocation functions are declared in a namespace scope other than global scope or declared static in global scope.
A deallocation function is a destroying operator delete if it has at least two parameters and its second parameter is of type std​::​destroying_­delete_­t.
A destroying operator delete shall be a class member function named operator delete.
[Note 1:
Array deletion cannot use a destroying operator delete.
— end note]
Each deallocation function shall return void.
If the function is a destroying operator delete declared in class type C, the type of its first parameter shall be C*; otherwise, the type of its first parameter shall be void*.
A deallocation function may have more than one parameter.
A usual deallocation function is a deallocation function whose parameters after the first are
  • optionally, a parameter of type std​::​destroying_­delete_­t, then
  • optionally, a parameter of type std​::​size_­t37, then
  • optionally, a parameter of type std​::​align_­val_­t.
A destroying operator delete shall be a usual deallocation function.
A deallocation function may be an instance of a function template.
Neither the first parameter nor the return type shall depend on a template parameter.
A deallocation function template shall have two or more function parameters.
A template instance is never a usual deallocation function, regardless of its signature.
If a deallocation function terminates by throwing an exception, the behavior is undefined.
The value of the first argument supplied to a deallocation function may be a null pointer value; if so, and if the deallocation function is one supplied in the standard library, the call has no effect.
If the argument given to a deallocation function in the standard library is a pointer that is not the null pointer value ([basic.compound]), the deallocation function shall deallocate the storage referenced by the pointer, ending the duration of the region of storage.
The global operator delete(void*, std​::​size_­t) precludes use of an allocation function void operator new(std​::​size_­t, std​::​size_­t) as a placement allocation function ([diff.cpp11.basic]).