<html>
<head>
<base href="http://llvm.org/bugs/" />
</head>
<body><table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW --- - generic lambda: failed to interpret a string when the string is in a pair"
href="http://llvm.org/bugs/show_bug.cgi?id=22029">22029</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>generic lambda: failed to interpret a string when the string is in a pair
</td>
</tr>
<tr>
<th>Product</th>
<td>clang
</td>
</tr>
<tr>
<th>Version</th>
<td>unspecified
</td>
</tr>
<tr>
<th>Hardware</th>
<td>All
</td>
</tr>
<tr>
<th>OS</th>
<td>All
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>normal
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
<tr>
<th>Component</th>
<td>C++14
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>wang_feng@live.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvmbugs@cs.uiuc.edu
</td>
</tr>
<tr>
<th>Classification</th>
<td>Unclassified
</td>
</tr></table>
<p>
<div>
<pre>Example code:
template< typename ... Args >
auto list( Args ... args )
{
return [=]( auto func ){ return func( args... ); };
}
template< typename List_1, typename List_2 >
auto cons( List_1 list_1, List_2 list_2 )
{
return list_1( [=]( auto ... args_1 ){ return list_2( [=]( auto ... args_2
){ return list( args_1..., args_2...); } ); } );
}
template< typename Func, typename List >
auto map( Func func, List the_list )
{
return the_list( [=]( auto ... elems ){ return list( func(elems)... ); } );
}
#include <string>
#include <utility>
#include <type_traits>
#include <iostream>
int main()
{
auto mfl = cons( cons( list( std::make_pair( std::string{"f1"}, [](int i){
return i; } ) ),
list( std::make_pair( std::string{"f2"}, []( double x, double
y){ return x*y; } ) ) ),
list( std::make_pair( std::string{"f3"}, [](std::string s){
return s+s; } ) ) );
auto pair_printer = []( auto the_pair ) { std::cout << "id:" <<
the_pair.first << "\n"; return the_pair; };
map( pair_printer, mfl );
return 0;
}
the expected output is(gcc 4.9 gives):
id:f1
id:f2
id:f3
but clang(3.4 and 3.5) gives:
id:f1
id: 4S� 4S�
id:4S��4S��4S��S���
�S��
84S��4S�
and clang 3.6 failed to link it.
An online version is here:
<a href="http://melpon.org/wandbox/permlink/6dnNByDwiAAl27as">http://melpon.org/wandbox/permlink/6dnNByDwiAAl27as</a>
Some discussion in stackoverflow is here:
<a href="http://stackoverflow.com/questions/27482444/strange-behaviour-of-generalized-lambda-in-c14">http://stackoverflow.com/questions/27482444/strange-behaviour-of-generalized-lambda-in-c14</a></pre>
</div>
</p>
<hr>
<span>You are receiving this mail because:</span>
<ul>
<li>You are on the CC list for the bug.</li>
</ul>
</body>
</html>