[R-sig-hpc] How to shorten an atomic vector without copying?

[Simon Urbanek]

On Apr 15, 2012, at 6:54 AM, Jens Oehlschlägel wrote:

> Hi Performance gurus,
> 
> Does any of you know how to shorten an atomic vector without copying the contents to a new vector? The official SET_LENGTH and lengthgets seem to create a new atomic vector rather than realloc the old one.
> 

You can use SETLENGTH(x) to shorten vectors, but be aware that it doesn't change the allocated memory.

There is no way to realloc (besides, in practice realloc is typically just a shortcut for allocating more and copying the contents ).

Cheers,
Simon