<html>
<head>
<base href="https://bugs.llvm.org/">
</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 - Invalid template parameter"
href="https://bugs.llvm.org/show_bug.cgi?id=42213">42213</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>Invalid template parameter
</td>
</tr>
<tr>
<th>Product</th>
<td>clang
</td>
</tr>
<tr>
<th>Version</th>
<td>trunk
</td>
</tr>
<tr>
<th>Hardware</th>
<td>PC
</td>
</tr>
<tr>
<th>OS</th>
<td>Linux
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>enhancement
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
<tr>
<th>Component</th>
<td>C++
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>zhonghao@pku.org.cn
</td>
</tr>
<tr>
<th>CC</th>
<td>blitzrakete@gmail.com, dgregor@apple.com, erik.pilkington@gmail.com, llvm-bugs@lists.llvm.org, richard-llvm@metafoo.co.uk
</td>
</tr></table>
<p>
<div>
<pre>My clang is 9.0.0, and the code is:
template < bool, class > struct A {};
template < class, int > void f () {};
template < class T, int >
decltype (f < T, 1 >) f (T t, typename A < t == 0, int >::type) {};
struct B {};
int main ()
{
f < B, 0 >;
return 0;
}
clang accepts the code, but icc, gcc, and msvc all reject it:
gcc:
<source>:5:56: error: wrong number of template arguments (1, should be 2)
5 | decltype (f < T, 1 >) f (T t, typename A < t == 0, int >::type) {};
| ^
<source>:2:33: note: provided for 'template<bool <anonymous>, class> struct A'
2 | template < bool, class > struct A {};
| ^
<source>:5:40: error: expected nested-name-specifier before 'A'
5 | decltype (f < T, 1 >) f (T t, typename A < t == 0, int >::type) {};
| ^
<source>:5:56: error: wrong number of template arguments (1, should be 2)
5 | decltype (f < T, 1 >) f (T t, typename A < t == 0, int >::type) {};
| ^
<source>:2:33: note: provided for 'template<bool <anonymous>, class> struct A'
2 | template < bool, class > struct A {};
| ^
<source>:5:56: error: wrong number of template arguments (1, should be 2)
5 | decltype (f < T, 1 >) f (T t, typename A < t == 0, int >::type) {};
| ^
<source>:2:33: note: provided for 'template<bool <anonymous>, class> struct A'
2 | template < bool, class > struct A {};
| ^
<source>:5:56: error: wrong number of template arguments (1, should be 2)
5 | decltype (f < T, 1 >) f (T t, typename A < t == 0, int >::type) {};
| ^
<source>:2:33: note: provided for 'template<bool <anonymous>, class> struct A'
2 | template < bool, class > struct A {};
| ^
<source>:5:42: error: expected ',' or '...' before '<' token
5 | decltype (f < T, 1 >) f (T t, typename A < t == 0, int >::type) {};
| ^
Compiler returned: 1
icc:
<source>(5): error: a parameter is not allowed
decltype (f < T, 1 >) f (T t, typename A < t == 0, int >::type) {};
^
compilation aborted for <source> (code 2)
Compiler returned: 2
msvc:
example.cpp
<source>(5): error C2975: 'unnamed-parameter': invalid template argument for
'A', expected compile-time constant expression
<source>(2): note: see declaration of 'unnamed-parameter'
<source>(5): error C2039: 'type': is not a member of 'A<false,int>'
<source>(5): note: see declaration of 'A<false,int>'
<source>(5): error C4430: missing type specifier - int assumed. Note: C++ does
not support default-int
<source>(11): warning C4551: function call missing argument list
Compiler returned: 2</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>