seq_len

In a post on R-devel, Prof Ripley add the following comment
| > BTW, 1:dim(names)[1] is dangerous: it could be 1:0.  That was the
| > motivation for seq_len.

I use the dim(names)[1] and dim(x)[2] along with length(x) with varying 
levels of frustration depending on the object which I am trying to get 
the dimensions.  I found the reference to seq_len interesting since it 
is a function that I have never seen (probably just missed it reading 
the docs).

I was hoping someone could expand on the benefits of seq_len.

Happy Holidays
Joe