Hello,

In the current C++ draft (august 2019), the grammar for a pp-import
(http://eel.is/c++draft/cpp.import#nt:pp-import) allows for additional
pp-tokens after the header-name or the header-name-tokens.

The current version of that section is the result of P1703:
"Recognizing Header Unit Imports Requires Full Preprocessing"
(http://open-std.org/JTC1/SC22/WG21/docs/papers/2019/p1703r1.html).
Before the changes caused by this proposal, the grammar still allowed
for preprocessing tokens tokens after the header-name or the
header-name-tokens, but in the form of a pp-import-suffix. (section
[cpp.module] of P1103
(http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1103r3.pdf)).

What is the reasoning behind allowing additional, unused preprocessing
tokens in this context?

Thank you.