<html><head><style type='text/css'>p { margin: 0; }</style></head><body><div style='font-family: courier new,courier,monaco,monospace,sans-serif; font-size: 10pt; color: #000000'><div><font face="courier new, courier, monaco, monospace, sans-serif"><span style="font-size: 13.3333px;">This compiles in clang 3.8 but I believe it should not:</span></font></div><font face="courier new, courier, monaco, monospace, sans-serif"><div style="font-size: 13.3333px;"><font face="courier new, courier, monaco, monospace, sans-serif"><span style="font-size: 13.3333px;"><br></span></font></div></font><blockquote style="margin: 0 0 0 40px; border: none; padding: 0px;"><font face="courier new, courier, monaco, monospace, sans-serif"><div><span style="font-size: 13.3333px;"><div>template< class T = int ></div></span></div></font><font face="courier new, courier, monaco, monospace, sans-serif"><div><span style="font-size: 13.3333px;"><div>struct A</div></span></div></font><font face="courier new, courier, monaco, monospace, sans-serif"><div><span style="font-size: 13.3333px;"><div>{</div></span></div></font><font face="courier new, courier, monaco, monospace, sans-serif"><div><span style="font-size: 13.3333px;"><div><span class="Apple-tab-span" style="white-space:pre"> </span>struct B {};</div></span></div></font><font face="courier new, courier, monaco, monospace, sans-serif"><div><span style="font-size: 13.3333px;"><div><br></div></span></div></font><font face="courier new, courier, monaco, monospace, sans-serif"><div><span style="font-size: 13.3333px;"><div><span class="Apple-tab-span" style="white-space:pre"> </span>const B* test (const B* b) const;</div></span></div></font><font face="courier new, courier, monaco, monospace, sans-serif"><div><span style="font-size: 13.3333px;"><div>};</div></span></div></font><font face="courier new, courier, monaco, monospace, sans-serif"><div><span style="font-size: 13.3333px;"><div><br></div></span></div></font><font face="courier new, courier, monaco, monospace, sans-serif"><div><span style="font-size: 13.3333px;"><div>template< class T ></div></span></div></font><font face="courier new, courier, monaco, monospace, sans-serif"><div><span style="font-size: 13.3333px;"><div>inline auto A< T >::test (const B* const b) const -> const B*</div></span></div></font><font face="courier new, courier, monaco, monospace, sans-serif"><div><span style="font-size: 13.3333px;"><div>{</div></span></div></font><font face="courier new, courier, monaco, monospace, sans-serif"><div><span style="font-size: 13.3333px;"><div><span class="Apple-tab-span" style="white-space:pre"> </span>return ++b;</div></span></div></font><font face="courier new, courier, monaco, monospace, sans-serif"><div><span style="font-size: 13.3333px;"><div>}</div></span></div></font><font face="courier new, courier, monaco, monospace, sans-serif"><div><span style="font-size: 13.3333px;"><div><br></div></span></div></font><font face="courier new, courier, monaco, monospace, sans-serif"><div><span style="font-size: 13.3333px;"><div>int main()</div></span></div></font><font face="courier new, courier, monaco, monospace, sans-serif"><div><span style="font-size: 13.3333px;"><div>{</div></span></div></font><font face="courier new, courier, monaco, monospace, sans-serif"><div><span style="font-size: 13.3333px;"><div> A<> m;</div></span></div></font><font face="courier new, courier, monaco, monospace, sans-serif"><div><span style="font-size: 13.3333px;"><div> const A<>::B* b = 0;</div></span></div></font><font face="courier new, courier, monaco, monospace, sans-serif"><div><span style="font-size: 13.3333px;"><div> b = m.test (b);</div></span></div></font><font face="courier new, courier, monaco, monospace, sans-serif"><div><span style="font-size: 13.3333px;"><div>}</div></span></div></font></blockquote><font face="courier new, courier, monaco, monospace, sans-serif"><div style="font-size: 13.3333px;"><font face="courier new, courier, monaco, monospace, sans-serif"><span style="font-size: 13.3333px;"><br></span></font></div><div style="font-size: 13.3333px;"><font face="courier new, courier, monaco, monospace, sans-serif"><span style="font-size: 13.3333px;">Here is the same code in </span></font><span style="font-size: 13.3333px;">coliru:</span></div></font><font face="courier new, courier, monaco, monospace, sans-serif"><div style="font-size: 13.3333px;"><font face="courier new, courier, monaco, monospace, sans-serif"><span style="font-size: 13.3333px;"><br></span></font></div><span style="font-size: 13.3333px;">http://coliru.stacked-crooked.com/a/55a3a6e7d28e8a5d</span><br></font><div><font face="courier new, courier, monaco, monospace, sans-serif"><span style="font-size: 13.3333px;"><br></span></font></div><div><font face="courier new, courier, monaco, monospace, sans-serif"><span style="font-size: 13.3333px;">gcc reports the error I was expecting:</span></font></div><div><font face="courier new, courier, monaco, monospace, sans-serif"><span style="font-size: 13.3333px;"><br></span></font></div><blockquote style="margin: 0 0 0 40px; border: none; padding: 0px;"><div><font face="courier new, courier, monaco, monospace, sans-serif"><span style="font-size: 13.3333px;"><div>main.cpp: In instantiation of 'const A<T>::B* A<T>::test(const A<T>::B*) const [with T = int]':</div></span></font></div><div><font face="courier new, courier, monaco, monospace, sans-serif"><span style="font-size: 13.3333px;"><div>main.cpp:19:18: required from here</div></span></font></div><div><font face="courier new, courier, monaco, monospace, sans-serif"><span style="font-size: 13.3333px;"><div>main.cpp:12:9: error: increment of read-only parameter 'b'</div></span></font></div><div><font face="courier new, courier, monaco, monospace, sans-serif"><span style="font-size: 13.3333px;"><div> return ++b;</div></span></font></div></blockquote><div><br></div><div><font face="courier new, courier, monaco, monospace, sans-serif"><span style="font-size: 13.3333px;"><div>This is a very non-critical bug<span style="font-size: 13.3333px;"> (</span><span style="font-size: 13.3333px;">if it even is a bug) and</span><span style="font-size: 13.3333px;"> I do not need a fix but I thought I would point it out because I happened to notice.</span></div></span></font><font face="courier new, courier, monaco, monospace, sans-serif"><span style="font-size: 13.3333px;"><div><br></div><div>Thanks,</div><div>Adam Burr</div><div>Blue Sky Studios</div></span></font></div></div></body></html>