[ublas] --(m.end1()) fails

From: Gunter Winkler (guwi17_at_[hidden])
Date: 2007-02-15 08:23:35

Hello,

in the current implementation of compressed_matrix::const_iterator1 the 
iterator is not decrementable when it is at end:

compressed_matrix::const_iterator1 it = m.end1();
--it_end; // throws a bad_index() exception

However, the condition to be dereferencable (== not at end) is _not_ required 
for the decrement operator. (Although it is required for the increment 
operator.)

The patch fixes this.

mfg
Gunter

PS: my line numbers may be quite different from the ones of the CVS