built-in NAMED(obj) from within R

On Friday, November 9, 2012, Simon Urbanek wrote:

On Nov 9, 2012, at 8:00 AM, Hadley Wickham wrote:

The goal is to ascertain whether a copy of an object has been made.

Then :

   ?tracemem

One demonstration of using both together is here :

   http://stackoverflow.com/a/10312843/403310

Note that tracemem detects duplications (in a technical R sense), not
copies - i.e.

x <- 1:10
tracemem(x)
x[11] <- 11L

although all the individual elements are copied,

No elements are copied - this is a subassignment and it is done in place hence there is neither duplication nor copying - simply the value of the 11th element is changed.

 But there was no 11th element - it was only 10 long.