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<base href="https://llvm.org/bugs/" />
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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW --- - Give better error message for template argument deduction failure when taking the address of a function template"
href="https://llvm.org/bugs/show_bug.cgi?id=25660">25660</a>
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<th>Summary</th>
<td>Give better error message for template argument deduction failure when taking the address of a function template
</td>
</tr>
<tr>
<th>Product</th>
<td>clang
</td>
</tr>
<tr>
<th>Version</th>
<td>unspecified
</td>
</tr>
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<th>Hardware</th>
<td>PC
</td>
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<th>OS</th>
<td>All
</td>
</tr>
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<th>Status</th>
<td>NEW
</td>
</tr>
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<th>Severity</th>
<td>normal
</td>
</tr>
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<th>Priority</th>
<td>P
</td>
</tr>
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<th>Component</th>
<td>Frontend
</td>
</tr>
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<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>ehsan@mozilla.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
</tr>
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<th>Classification</th>
<td>Unclassified
</td>
</tr></table>
<p>
<div>
<pre>Code:
#include <utility>
using FuncType1 = void(*)();
using FuncType2 = void(*)(int);
using FuncType3 = void(*)(char, float);
struct Symbols {
FuncType1 f1;
FuncType2 f2;
FuncType3 f3;
};
Symbols* GetOriginalSymbols();
Symbols* GetSymbols();
template <typename... Args>
void DebugWrapperf1(Args&&... args) {
GetOriginalSymbols()->f1(args...);
}
template <typename... Args>
void DebugWrapperf2(Args&&... args) {
GetOriginalSymbols()->f2(args...);
}
void Initialize() {
GetSymbols()->f1 = &DebugWrapperf1;
GetSymbols()->f2 = &DebugWrapperf2;
}
Clang's error:
$ clang++ -c test.cpp -std=c++11
test.cpp:28:22: error: assigning to 'FuncType2' (aka 'void (*)(int)') from
incompatible type '<overloaded function type>'
GetSymbols()->f2 = &DebugWrapperf2;
^ ~~~~~~~~~~~~~~~
test.cpp:22:6: note: candidate function
void DebugWrapperf2(Args&&... args) {
^
1 error generated.
It would be helpful if clang told us that the issue here is that Arg&& cannot
be matched against int. It would be really helpful if clang also gave a fix-it
hint to get rid of the && in DebugWrapperf2's variadic template argument.</pre>
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