The 'Oven' port...
<div><br></div><div><a href="http://dl.dropbox.com/u/1682460/git/OvenToBoost/libs/range/doc/html/range_extension/design_rationale/regular_op.html">http://dl.dropbox.com/u/1682460/git/OvenToBoost/libs/range/doc/html/range_extension/design_rationale/regular_op.html</a></div>

<div><br></div><div>makes much of its &#39;regular&#39; operator, which is used to fix this problem</div><div><br></div><div><div><font face="courier new, monospace">using boost::lambda::_1;</font></div><div><font face="courier new, monospace">for_each_(r | filtered(_1 % 2 == 0), f);          // Error! Can&#39;t default construct/copy assign</font></div>

<div><font face="courier new, monospace">for_each_(r | filtered(regular(_1 % 2 == 0)), f); // OK</font></div></div><div><br></div><div>However, AFAICS this is not a problem in current-ishBoost (1.47). Has this ever been a problem? Can anyone</div>

<div>comment on its general  provenance?</div><div><br></div><div>Thx, Rob.</div><div><br></div>