6 Basic concepts [basic]

6.7 Storage duration [basic.stc]

6.7.4 Dynamic storage duration [basic.stc.dynamic]

6.7.4.2 Deallocation functions [basic.stc.dynamic.deallocation]

1
#
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.
2
#
Each deallocation function shall return void and its first parameter shall be void*.
A deallocation function may have more than one parameter.
A usual deallocation function is a deallocation function that has:
  • (2.1)
    exactly one parameter; or
  • (2.2)
    exactly two parameters, the type of the second being either std​::​align_­val_­t or std​::​size_­t39; or
  • (2.3)
    exactly three parameters, the type of the second being std​::​size_­t and the type of the third being std​::​align_­val_­t.
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.
[ Note
:
That is, a deallocation function template shall have a first parameter of type void* and a return type of void (as specified above).
— end note
 ]
A deallocation function template shall have two or more function parameters.
A template instance is never a usual deallocation function, regardless of its signature.
3
#
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.
4
#
If the argument given to a deallocation function in the standard library is a pointer that is not the null pointer value ([conv.ptr]), the deallocation function shall deallocate the storage referenced by the pointer, ending the duration of the region of storage.
39)
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]).