Rationale (August, 2011):

As given in the preceding note.

Note (March, 2008):

This issue should be closed as NAD as a result of the rewrite of 7.7 [expr.const] in conjunction with the constexpr proposal.

Does an explicit temporary of an integral type qualify as an integral constant expression? For instance,

    void* p = int();    // well-formed?

It would appear to be, since int() is an explicit type conversion according to 7.6.1.4 [expr.type.conv] (at least, it's described in a section entitled "Explicit type conversion") and type conversions to integral types are permitted in integral constant expressions (7.7 [expr.const]). However, this reasoning is somewhat tenuous, and some at least have argued otherwise.