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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - Clang is too strict on object lifetime for automatic storage duration"
href="https://bugs.llvm.org/show_bug.cgi?id=48732">48732</a>
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<th>Summary</th>
<td>Clang is too strict on object lifetime for automatic storage duration
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<th>Product</th>
<td>clang
</td>
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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>other
</td>
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<th>Status</th>
<td>NEW
</td>
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<th>Severity</th>
<td>normal
</td>
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<th>Priority</th>
<td>P
</td>
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<th>Component</th>
<td>-New Bugs
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<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
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<th>Reporter</th>
<td>minatsuh@microsoft.com
</td>
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<th>CC</th>
<td>htmldeveloper@gmail.com, llvm-bugs@lists.llvm.org, neeilans@live.com, richard-llvm@metafoo.co.uk
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<div>
<pre>Behavior displayed in <a href="https://godbolt.org/z/n5Wenn">https://godbolt.org/z/n5Wenn</a>
Reproducing code repeated here:
template <typename T>
constexpr void f(T& t) {
t.~T();
}
struct S {
constexpr ~S() { }
};
constexpr int g() {
{
// This should be fine, provided there are no more reads of
// 'i' before a new object lifetime is created.
int i = 0;
f(i);
}
{
// This should be UB: S::~S() is a non-trivial dtor.
S s{};
f(s);
}
return 0;
}
static_assert(g() == 0);
Relevant Standardese:
* <a href="http://eel.is/c++draft/basic.life#5">http://eel.is/c++draft/basic.life#5</a>
* <a href="http://eel.is/c++draft/basic.life#9">http://eel.is/c++draft/basic.life#9</a>
Currently, Clang errors on the first block of code using int i, though I
believe the first block of code should be fine as int does not have a
non-trivial destructor (<a href="http://eel.is/c++draft/basic.life#9">http://eel.is/c++draft/basic.life#9</a>). Note that the
second block should produce an error (which Clang does) as struct S does have a
non-trivial destructor.</pre>
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</p>
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