How to declare a function accept arbitrary length array of rvalue

Question

Suppose I have a function like this:

void MyFun(MyClass* p){

}

Where p is actually an unknown length array. How can I overloaded it to accept an array of rvalue MyClass.

use std::array or std::vector, there is no way to know the size of the array by the pointer alone — AndersK, Apr 01 '18 at 10:54
@JohnZwinck I never mentioned that I want to know the size. How come that question has anything to do with my problem? — J. Doe, Apr 01 '18 at 11:48
There is no such thing as an array of rvalues. "rvalue" is an expression category, not a type. What are you actually trying to do? — Lightness Races in Orbit, Apr 01 '18 at 12:23

einpoklum · Accepted Answer · 2018-04-01T13:45:43.307

Basically, you cannot - since being an rvalue is not really a proper part of the type system. There's no "pointer to rvalue T" or anything like that. Also, because using a pointer means that the pointed-to object could be any subclass of MyValue (that is also a reason I would not try something like reinterpreting the pointer as an std::array<MyClass, 123>, even if I knew the length to be 123).

I suggest you wrap your raw array in some class (dumb name for it: BunchOfMyClasses), and have:

void MyFun(const BunchOfMyClasses &);
void MyFun(BunchOfMyClasses &&);

as the overloads.

How to declare a function accept arbitrary length array of rvalue

1 Answers1