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<base href="http://llvm.org/bugs/" />
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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW --- - Premature instantiation of special member function declarations"
href="http://llvm.org/bugs/show_bug.cgi?id=19196">19196</a>
</td>
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<tr>
<th>Summary</th>
<td>Premature instantiation of special member function declarations
</td>
</tr>
<tr>
<th>Product</th>
<td>clang
</td>
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<th>Version</th>
<td>unspecified
</td>
</tr>
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<th>Hardware</th>
<td>PC
</td>
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<th>OS</th>
<td>Linux
</td>
</tr>
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<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>normal
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
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<th>Component</th>
<td>C++11
</td>
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<tr>
<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
</td>
</tr>
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<th>Reporter</th>
<td>dblaikie@gmail.com
</td>
</tr>
<tr>
<th>CC</th>
<td>chandlerc@gmail.com, dgregor@apple.com, llvmbugs@cs.uiuc.edu
</td>
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<th>Classification</th>
<td>Unclassified
</td>
</tr></table>
<p>
<div>
<pre>Clang seems to prematurely instantiate the declaration of the copy constructor
of std::function<bar()> when seen in the definition of 'foo' below. This causes
Clang to reject the following (due to what we believe is a libstdc++ bug) under
<a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED FIXED - Need to add product version numbers"
href="show_bug.cgi?id=1">BUG1</a> (and <a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED FIXED - Customize Bugzilla to have some LLVM flavah"
href="show_bug.cgi?id=2">BUG2</a>). GCC only rejects <a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED FIXED - Customize Bugzilla to have some LLVM flavah"
href="show_bug.cgi?id=2">BUG2</a> but accepts <a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED FIXED - Need to add product version numbers"
href="show_bug.cgi?id=1">BUG1</a>.
Are we allowed to instantiate that member function declaration?
#include <functional>
#include <type_traits>
struct bar;
#if <a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED FIXED - Need to add product version numbers"
href="show_bug.cgi?id=1">BUG1</a>
struct foo { std::function<bar ()> f; };
#elif <a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED FIXED - Customize Bugzilla to have some LLVM flavah"
href="show_bug.cgi?id=2">BUG2</a>
int i = std::is_copy_constructible<std::function<bar()>>::value;
#else
std::function<bar ()> b;
#endif
struct bar { };
int main() {
std::function<bar ()> g([] { return bar(); });
}</pre>
</div>
</p>
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