// Compiled on MacOS using:// clang++ -c -std=c++2a -gdwarf-4 -O0 -o accel-imported-declaration.macho-arm64.onamespace A {namespace B {namespace C {int a = -1;}// namespace C}// namespace Bnamespace C =B::C;using namespaceB::C;usingB::C::a;}// namespace A