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PiliLatiesa opened this issue Oct 7, 2024 · 4 comments · Fixed by #111457
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Clang++ fails to match template template parameters as function arguments #111363

PiliLatiesa opened this issue Oct 7, 2024 · 4 comments · Fixed by #111457
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@mizvekov
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clang:frontend Language frontend issues, e.g. anything involving "Sema" confirmed Verified by a second party regression:19 Regression in 19 release

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@PiliLatiesa
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Clang++ trunk started rejecting the following testcase (adapted from https://eel.is/c++draft/temp#arg.template-example-3). Clang 19 accepts it. It's a recent regression.

template <template <class, class...> class TT, class T1, class... Rest>
void f(TT<T1, Rest...> const &) {}

template <typename T1> struct A {};

int main()
{ 
  A<int> a;
  f(a);   // bogus "no matching function for call to 'f'"
}
@github-actions github-actions bot added the clang Clang issues not falling into any other category label Oct 7, 2024
@zyn0217 zyn0217 added clang:frontend Language frontend issues, e.g. anything involving "Sema" regression:19 Regression in 19 release and removed clang Clang issues not falling into any other category labels Oct 7, 2024
@llvmbot
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llvmbot commented Oct 7, 2024

@llvm/issue-subscribers-clang-frontend

Author: None (PiliLatiesa)

Clang++ trunk started rejecting the following testcase (adapted from https://eel.is/c++draft/temp#arg.template-example-3). Clang 19 accepts it. It's a recent regression. 
template &lt;template &lt;class, class...&gt; class TT, class T1, class... Rest&gt;
void f(TT&lt;T1, Rest...&gt; const &amp;) {}

template &lt;typename T1&gt; struct A {};

int main()
{ 
  A&lt;int&gt; a;
  f(a);   // bogus "no matching function for call to 'f'"
}

@zyn0217
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zyn0217 commented Oct 7, 2024

@mizvekov Is it also related to #96023?

@cor3ntin
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cor3ntin commented Oct 7, 2024

Yes #96023 (comment)

@shafik shafik added the confirmed Verified by a second party label Oct 7, 2024
@mizvekov mizvekov mentioned this issue Oct 8, 2024
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@mizvekov
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mizvekov commented Oct 8, 2024

This will be fixed by #111457

@mizvekov mizvekov self-assigned this Oct 8, 2024
zmodem added a commit that referenced this issue Oct 9, 2024
@zmodem
Revert "[clang] Finish implementation of P0522 (#96023)"
ada6372 
This caused Clang to reject valid code, see discussion on the PR
#96023 (comment)
and #111363

This reverts commit 6afe567 and
follow-up commit 9abb97f.
DanielCChen pushed a commit to DanielCChen/llvm-project that referenced this issue Oct 16, 2024
@mizvekov @DanielCChen
[clang] Implement TTP P0522 pack matching for deduced function templa…
4884fb4 
…te calls. (llvm#111457)

Clang previously missed implementing P0522 pack matching for deduced
function template calls.

Fixes llvm#111363
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@mizvekov mizvekov

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clang:frontend Language frontend issues, e.g. anything involving "Sema" confirmed Verified by a second party regression:19 Regression in 19 release
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[clang] Implement TTP P0522 pack matching for deduced function template calls. llvm/llvm-project
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@mizvekov @cor3ntin @shafik @llvmbot @PiliLatiesa @zyn0217