size of object ?

[Rayan jutt]

what is the size of object in c++ , if there is no data member in the class ?

[LB]

sizeof is required to return 1. This gets messy with inheritance/virtual inheritance/virtual functions though...

[andywestken]

sizeof is required to return at least 1.

Of course, implementations usually use the smallest possible value which satisfies this criterium.

Andy

From the standard:

Unless it is a bit-field (9.6), a most derived object shall have a non-zero size and shall occupy one or more bytes of storage. Base class subobjects may have zero size. An object of trivially copyable or standard-layout type (3.9) shall occupy contiguous bytes of storage.

[vlad from moscow]

@Nabeel Nazir

what is the size of object in c++ , if there is no data member in the class ?

It has a non-zero size.

Let assume that you decided to define an array of such a type. If the size of an object of a class without non-static data members would be equal to zero then the array had zero size and there would not be any sense to access elements of the array by index.