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<base href="https://bugs.llvm.org/">
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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - static data member "unresolved external symbol" if constexpr is used in its definition"
href="https://bugs.llvm.org/show_bug.cgi?id=34754">34754</a>
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<th>Summary</th>
<td>static data member "unresolved external symbol" if constexpr is used in its definition
</td>
</tr>
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<th>Product</th>
<td>clang
</td>
</tr>
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<th>Version</th>
<td>trunk
</td>
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<th>Hardware</th>
<td>PC
</td>
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<th>OS</th>
<td>Windows NT
</td>
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<th>Status</th>
<td>NEW
</td>
</tr>
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<th>Severity</th>
<td>normal
</td>
</tr>
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<th>Priority</th>
<td>P
</td>
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<th>Component</th>
<td>C++11
</td>
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<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
</td>
</tr>
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<th>Reporter</th>
<td>powerchord@web.de
</td>
</tr>
<tr>
<th>CC</th>
<td>dgregor@apple.com, llvm-bugs@lists.llvm.org
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<p>
<div>
<pre>// header.h
struct S { static int const i; };
// source.cpp
#include "header.h"
constexpr int const S::i = 0;
// main.cpp
#include "header.h"
int main()
{
return S::i; // error or OK, depending on "C++ Language Standard" in compiler
options
}
If compiled with clang and "ISO C++ Latest Draft Standard (/std:c++latest)":
linker error "unresolved external symbol"
If compiled with clang and "ISO C++17 Standard (/std:c++17)" or "ISO C++14
Standard (/std:c++14)": OK
If compiled with VC: OK in all cases
I'm using Visual Studio 2017 on Windows 10 64-bit and the latest clang for
Windows.
Can someone tell me what's going on here? Is this a bug in clang?
S::i has external linkage, but clang seems to transform it into internal
linkage if constexpr is in the definition. Why?</pre>
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