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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW " title="NEW --- - eagerly-instantiated entities whose templates are defined after the first point of instantiation don't get instantiated at all" href="https://urldefense.proofpoint.com/v2/url?u=https-3A__llvm.org_bugs_show-5Fbug.cgi-3Fid-3D24128&d=AwMBaQ&c=8hUWFZcy2Z-Za5rBPlktOQ&r=pF93YEPyB-J_PERP4DUZOJDzFVX5ZQ57vQk33wu0vio&m=BDub-xVA5CKr0Hpmqh7ZIuvf9qND8rDnr6epbV1KyuY&s=pKkL-sRDalz7cvM-OWODfarWU3qFEHB65TYk0BvVI_k&e=">24128</a>
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<th>Summary</th>
<td>eagerly-instantiated entities whose templates are defined after the first point of instantiation don't get instantiated at all
</td>
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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>Linux
</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
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<th>Component</th>
<td>C++
</td>
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<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
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<th>Reporter</th>
<td>richard-llvm@metafoo.co.uk
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<th>CC</th>
<td>dgregor@apple.com, llvmbugs@cs.uiuc.edu
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<th>Classification</th>
<td>Unclassified
</td>
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<p>
<div>
<pre>If a template specialization is referenced in a way that requires a definition,
but the definition of the template appears after the use, the instantiation is
never performed.
Examples through the ages:
// C++98:
template<typename T> struct X { static const int n; };
int k = X<int>::n;
template<typename T> const int X<T>::n = 5;
// C++11:
template<typename T> constexpr int f();
int k = f<int>();
template<typename T> constexpr int f() { return 5; }
// C++14:
template<typename T> extern const int n;
int k = n<int>;
template<typename T> const int n = 5;
These are valid, and should cause the instantiation of the relevant template,
according to C++14 [temp]/6, which requires the template to "be defined in
every translation unit in which it is implicitly instantiated", but doesn't
require the definition to precede the use.</pre>
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