https://svn.boost.org/trac10/ticket/9737 <p> In boost spirit classic, when using position_iterator with istreambuf_iterator&lt;char&gt;, the underlying iterator_adaptor::deference() might return a reference to temporary: </p> <p> For example with clang34/libc++: </p> <pre class="wiki">$ clang++34 -O2 -Wall test-boost.cpp -o test-boost source/boost/boost/iterator/iterator_adaptor.hpp:310:18: warning: returning reference to local temporary object [-Wreturn-stack-address] { return *m_iterator; } ^~~~~~~~~~~ </pre><p> or with gcc47/libstdc++ in c++11 mode: </p> <pre class="wiki">$ g++47 --std=c++11 -O2 -Wall test-boost.cpp -o test-boost source/boost/boost/iterator/iterator_adaptor.hpp:310:19: warning: returning reference to temporary [enabled by default] </pre><p> but not in default gcc47 default code (gnu++98): </p> <pre class="wiki">$ g++47 -O2 -Wall test-boost.cpp -o test-boost </pre><p> We tracked down this issue to istreambuf_iterator&lt;char&gt;::reference and istreambuf_iterator&lt;char&gt;::operator*() definition: </p> <ul><li>On clang3.4/libc++: </li></ul><p> istreambuf_iterator&lt;char&gt;::reference type is 'char' and istreambuf_iterator&lt;char&gt;::operator*() also returns a 'char'. </p> <ul><li>On gcc47/libstdc++ in c++11 mode: </li></ul><p> istreambuf_iterator&lt;char&gt;::reference type is 'char' and istreambuf_iterator&lt;char&gt;::operator*() also returns a 'char'. </p> <p> See: istreambuf_iterator::reference changes from _CharT&amp; to _CharT: <a class="ext-link" href="http://gcc.gnu.org/wiki/Cxx11AbiCompatibility"><span class="icon">​</span>http://gcc.gnu.org/wiki/Cxx11AbiCompatibility</a> </p> <ul><li>However on gcc47/libstdc++ in default mode: </li></ul><p> istreambuf_iterator&lt;char&gt;::reference type is 'char &amp;' where istreambuf_iterator&lt;char&gt;::operator*() returns a 'char'. </p> <blockquote> <p> And position_iterator being built from iterator_adaptor with: </p> </blockquote> <pre class="wiki"> typedef boost::iterator_adaptor&lt; main_iter_t, ForwardIterT, const_value_type, boost::forward_traversal_tag &gt; type; </pre><blockquote> <p> there is no 5th template type which defines iterator_adaptor 'Reference': </p> </blockquote> <pre class="wiki"> // Iterator Adaptor // ... // // Reference - the reference type of the resulting iterator, and in // particular, the result type of operator*(). If not supplied but // Value is supplied, Value&amp; is used. Otherwise // iterator_traits&lt;Base&gt;::reference is used. </pre><blockquote> <p> Thus by default, iterator_adaptor::deference() from a position_iterator built of istreambuf_iterator&lt;char&gt; returns a &amp;char, which is fine only when istreambuf_iterator&lt;char&gt;::reference type is also 'char &amp;'. </p> </blockquote> en-us /htdocs/site/boost.png https://svn.boost.org/trac10/ticket/9737 Trac 1.4.3 Julien Charbon <jcharbon@…> Tue, 04 Mar 2014 14:02:13 GMT https://svn.boost.org/trac10/ticket/9737 https://svn.boost.org/trac10/ticket/9737 <ul> <li><strong>attachment</strong> → <span class="trac-field-new">test-boost.cpp</span> </li> </ul> <p> Simple test case example </p> Ticket Julien Charbon <jcharbon@…> Tue, 04 Mar 2014 14:10:41 GMT https://svn.boost.org/trac10/ticket/9737 https://svn.boost.org/trac10/ticket/9737 <ul> <li><strong>attachment</strong> → <span class="trac-field-new">position_iterator.patch</span> </li> </ul> <p> Patch that fix this specific issue (open to discussion) </p> Ticket Julien Charbon <jcharbon@…> Tue, 04 Mar 2014 14:17:28 GMT https://svn.boost.org/trac10/ticket/9737#comment:3 https://svn.boost.org/trac10/ticket/9737#comment:3 <ul> <li><strong>status</strong> <span class="trac-field-old">new</span> → <span class="trac-field-new">closed</span> </li> <li><strong>resolution</strong> → <span class="trac-field-new">fixed</span> </li> </ul> <p> fixed in <a class="ext-link" href="https://github.com/boostorg/spirit/pull/422"><span class="icon">​</span>https://github.com/boostorg/spirit/pull/422</a> </p> Ticket