6 Basics [basic]

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.

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

• (3.1)
  optionally, a parameter of type std​::​destroying_­delete_­t, then
• (3.2)
  optionally, a parameter of type std​::​size_­t37, then
• (3.3)
  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, the deallocation function shall deallocate the storage referenced by the pointer, ending the duration of the region of storage.