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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - Wrong error "template template argument has different template argument than parameters than its corresponding template template parameter""
href="https://bugs.llvm.org/show_bug.cgi?id=49224">49224</a>
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<th>Summary</th>
<td>Wrong error "template template argument has different template argument than parameters than its corresponding template template parameter"
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<th>Product</th>
<td>clang
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<th>Version</th>
<td>trunk
</td>
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<th>Hardware</th>
<td>PC
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<th>OS</th>
<td>Linux
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<th>Status</th>
<td>NEW
</td>
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<th>Severity</th>
<td>enhancement
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<th>Priority</th>
<td>P
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<th>Component</th>
<td>C++17
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<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
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<th>Reporter</th>
<td>gabravier@gmail.com
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<th>CC</th>
<td>blitzrakete@gmail.com, erik.pilkington@gmail.com, llvm-bugs@lists.llvm.org, richard-llvm@metafoo.co.uk
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<p>
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<pre>template <class T, class U, class A = int>
struct X {};
template <template <class, class> class T>
struct Y {};
using type = Y<X>;
In C++20 mode, GCC and MSVC build this fine, while Clang complains that
"template template argument has different template argument than parameters
than its corresponding template template parameter"
I believe <a href="https://eel.is/c++draft/temp.arg.template#example-2">https://eel.is/c++draft/temp.arg.template#example-2</a> means this should
work. -frelaxed-template-template-args makes it work, but I don't think that
should be required.
See also Godbolt comparison here: <a href="https://godbolt.org/z/oefM73">https://godbolt.org/z/oefM73</a></pre>
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