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

[Jens Oehlschlägel]

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.

Jens Oehlschlägel