This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 112e. See http://www.open-std.org/jtc1/sc22/wg21/ for the official list.
[Voted into the WP at the November, 2010 meeting.]
std::nullptr_t is not currently allowed by 13.2 [temp.param] paragraph 4 to be used as the type of a non-type template parameter. However, this could arise for a template with a non-type template parameter with a dependent type in a template intended for use with pointers, e.g.,
template<typename T, T t> void f(); ... f<std::nullptr_t, nullptr>();
or in a case of delegation.
Proposed resolution (September, 2010):
Change 13.2 [temp.param] paragraph 4 as follows:
A non-type template-parameter shall have one of the following (optionally cv-qualified) types:
integral or enumeration type,
pointer to object or pointer to function,
lvalue reference to object or lvalue reference to function,
pointer to member