http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54813
Bug #: 54813
Summary: NULL pointer conversion fails for template code
Classification: Unclassified
Product: gcc
Version: 4.6.3
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: tjab...@gmail.com
int foo(int i);
template<class Fun> static void bar(Fun fun, char[][sizeof(fun(0))]) {}
void baz() {
// With an explicit template parameter, 0 is converted to a multidimensional
// array
bar<int (*)(int)>(foo, 0); // succeeds
// The template type is inferred when a has the right type.
char a[4][sizeof(foo(0))];
bar(foo, a); // succeeds
// Combining the two previous examples fails in g++ but is accepted by
clang++.
// Compilers that emit errors for this line: g++ 4.4.7, 4.5.3, 4.6.3
// Compilers that will compile this line: clang++ 3.2
bar(foo, 0); // failure
}
Error message with g++ 4.6.3:
test.cc: In function ‘void baz()’:
test.cc:9:13: error: no matching function for call to ‘bar(int (&)(int), int)’
test.cc:9:13: note: candidate is:
test.cc:3:33: note: template<class Fun> void bar(Fun, char (*)[sizeof
(fun(0))])
