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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 - template lambda with default value can't be called if passing argument type doesn't match default value type"
href="https://bugs.llvm.org/show_bug.cgi?id=46648">46648</a>
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<th>Summary</th>
<td>template lambda with default value can't be called if passing argument type doesn't match default value type
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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>All
</td>
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<th>OS</th>
<td>All
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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++2a
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<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
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<th>Reporter</th>
<td>iurii.shtykov@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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<pre>interactive: <a href="https://godbolt.org/z/mM9hY8">https://godbolt.org/z/mM9hY8</a>
code:
_________________________
#include <string>
using std::literals::operator""s;
int main(){
auto error_lambda = []<class T = int>(T def = 1) -> T {
return def;
};
error_lambda(1);
error_lambda("error"s);
//but it works if default value = 0
auto good_lambda = []<class T = int>(T def = 0) -> T {
return def;
};
good_lambda(1);
good_lambda("good"s);
}
_________________________
output:
<source>:10:5: error: no matching function for call to object of type '(lambda
at <source>:5:25)'
error_lambda("error"s);
^~~~~~~~~~~~
<source>:5:25: note: candidate template ignored: substitution failure [with T =
std::__cxx11::basic_string<char, std::char_traits<char>,
std::allocator<char>>]: no viable conversion from 'int' to
'std::__cxx11::basic_string<char, std::char_traits<char>,
std::allocator<char>>'
auto error_lambda = []<class T = int>(T def = 1) -> T {
^ ~~~
1 error generated.
Compiler returned: 1</pre>
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