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<base href="https://bugs.llvm.org/">
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<body><table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - "Variable must be initialized by a constant expression" on std::min/max"
href="https://bugs.llvm.org/show_bug.cgi?id=47954">47954</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>"Variable must be initialized by a constant expression" on std::min/max
</td>
</tr>
<tr>
<th>Product</th>
<td>clang
</td>
</tr>
<tr>
<th>Version</th>
<td>11.0
</td>
</tr>
<tr>
<th>Hardware</th>
<td>PC
</td>
</tr>
<tr>
<th>OS</th>
<td>Windows NT
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>normal
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
<tr>
<th>Component</th>
<td>C++17
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>dmitriy.ovdienko@gmail.com
</td>
</tr>
<tr>
<th>CC</th>
<td>blitzrakete@gmail.com, erik.pilkington@gmail.com, llvm-bugs@lists.llvm.org, richard-llvm@metafoo.co.uk
</td>
</tr></table>
<p>
<div>
<pre>I cannot compile the following code:
```cpp
#include <algorithm>
static constexpr auto x = {1, 2, 3};
static constexpr auto y = std::min(x);
```
The error is:
=======================================================
bad.cpp:5:23: error: constexpr variable 'y' must be initialized by a constant
expression
static constexpr auto y = std::min(x);
^ ~~~~~~~~~~~
C:\msys64\mingw64\include\c++\10.2.0\bits/predefined_ops.h:43:16: note: read of
temporary is not allowed in a constant expression outside the expression that
created the
temporary
{ return *__it1 < *__it2; }
^
C:\msys64\mingw64\include\c++\10.2.0\bits/stl_algo.h:5636:6: note: in call to
'&__comp->operator()(&{1, 2, 3}[1], &{1, 2, 3}[0])'
if (__comp(__first, __result))
^
C:\msys64\mingw64\include\c++\10.2.0\bits/stl_algo.h:5660:14: note: in call to
'__min_element(&{1, 2, 3}[1], &{1, 2, 3}[3], {})'
return _GLIBCXX_STD_A::__min_element(__first, __last,
^
C:\msys64\mingw64\include\c++\10.2.0\x86_64-w64-mingw32\bits/c++config.h:400:25:
note: expanded from macro '_GLIBCXX_STD_A'
# define _GLIBCXX_STD_A std
^
C:\msys64\mingw64\include\c++\10.2.0\bits/stl_algo.h:3469:15: note: in call to
'min_element(&{1, 2, 3}[0], &{1, 2, 3}[3])'
{ return *std::min_element(__l.begin(), __l.end()); }
^
bad.cpp:5:27: note: in call to 'min({&{1, 2, 3}[0], 3})'
static constexpr auto y = std::min(x);
^
bad.cpp:3:27: note: temporary created here
static constexpr auto x = {1, 2, 3};
=======================================================
However following code does compile:
```cpp
#include <algorithm>
static constexpr auto y = std::min({1, 2, 3});
```
OS: Windows 10
Distribution: MSys2 (<a href="https://www.msys2.org/">https://www.msys2.org/</a>)
clang version 10.0.1 (<a href="https://github.com/Alexpux/MINGW-packages.git">https://github.com/Alexpux/MINGW-packages.git</a>
94b687508346d10cec7e8c769785f73da18b4e54)
Target: x86_64-w64-windows-gnu
Thread model: posix
InstalledDir: C:\msys64\mingw64\bin
The code above does not compile on clang 11 and trunk on <a href="https://godbolt.org/">https://godbolt.org/</a>
too.</pre>
</div>
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