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<base href="https://bugs.llvm.org/">
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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - tag-dispatching with variadic templates results in error "call is ambiguous""
href="https://bugs.llvm.org/show_bug.cgi?id=42872">42872</a>
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<th>Summary</th>
<td>tag-dispatching with variadic templates results in error "call is ambiguous"
</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>Windows NT
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<th>Status</th>
<td>NEW
</td>
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<th>Severity</th>
<td>enhancement
</td>
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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>tobias.loew@steag.com
</td>
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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>
<div>
<pre>Hi,
the following code results in:
<source>:29:5: error: call to 'bar' is ambiguous
bar(tag_select{}, 1.0, 2.0, 3.0, 4.0);
^~~
<source>:7:6: note: candidate function [with Ts = <double, double, double,
double>]
void bar(
^
<source>:20:6: note: candidate function [with T1 = tag_select, T2 = double, Ts
= <double, double, double>]
void bar(
^
1 error generated.
Compiler returned: 1
Tested with godbolt clang x86-64 trunk (on 8/2/2019) with -std=c++17
*************************************************************************
struct tag_select {};
template<
typename ...Ts
>
void bar(
tag_select,
Ts&& ... ts
)
{
}
template<
typename T1,
typename T2,
typename ...Ts
>
void bar(
T1&& t1,
T2&& t2,
Ts&& ... ts
)
{}
int main()
{
bar(tag_select{}, 1.0, 2.0, 3.0, 4.0);
}</pre>
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