I&#39;m not able to use the latest Boost release, so I&#39;ve plagarised some little<br>bits that are useful, and in the process might have missed something, so<br>bear with me.<br><br>I have this bit of code...<br><br><span style="font-family: courier new,monospace;">#include &lt;algorithm&gt;</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;">#include &lt;boost/range.hpp&gt;</span><br style="font-family: courier new,monospace;"><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;">template &lt; class SinglePassRange, class UnaryFunction &gt;</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;">    UnaryFunction for_each( SinglePassRange &amp; rng, UnaryFunction fun )</span><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;">{</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;">    return std::for_each( boost::begin( rng ), boost::end( rng ), fun );</span><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;">}</span><br style="font-family: courier new,monospace;">
<br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;">struct A { };</span><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;">void f( const A &amp; );</span><br style="font-family: courier new,monospace;">
<br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;">std::vector&lt; A &gt; generateVec( );</span><br style="font-family: courier new,monospace;"><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;">int main( )</span><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;">{</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;">    for_each( generateVec( ), f );</span><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;">}</span><br style="font-family: courier new,monospace;">
<br>which understandably fails to compile as I&#39;m passing an lvalue as non-const<br>reference. I can fix this by adding a const ref overload of for_each, but no such<br>overload exists in the real boost range header (AFAIK).<br>
<br>Returning containers by value seems to be the &#39;right way&#39; now, as RVO should<br>sort out the copy elision.<br><br>What I&#39;m doing in this code seems reasonable - should it be supported by<br>const ref overloads, or have I missed some &#39;gotcha&#39; somewhere?<br>
<br>Thanks,<br><br>- Rob.<br><br>