This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 115d. See http://www.open-std.org/jtc1/sc22/wg21/ for the official list.
2024-10-26
According to 6.5.1 [basic.lookup.general] paragraphs 2-3,
...A declaration X precedes a program point P in a translation unit L if P follows X, X inhabits a class scope and is reachable from P, or else...
A single search in a scope S for a name N from a program point P finds all declarations that precede P to which any name that is the same as N (6.1 [basic.pre]) is bound in S.
These rules cause problems for finding enumerators when qualified by an exported name of its enumeration type, unlike a member of a class. For example:
export module A; enum class X { x }; enum Y { y }; export module B; import A; export using XB = X; export using YB = Y; // client code import B; int main() { XB x = XB::x; // should be OK because definition of X is reachable, even // though A is not imported YB y = YB::y; // similarly OK YB z = ::y; // error, because y from module A is not visible }
It would seem that this problem could be addressed by changing “inhabits a class scope” to “does not inhabit a namespace scope.”