[Bug c++/70587] New: 0e1_p+0 should not be parsed as a single pp-number in C++14 and earlier

[rs2740 at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70587

            Bug ID: 70587
           Summary: 0e1_p+0 should not be parsed as a single pp-number in
                    C++14 and earlier
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: rs2740 at gmail dot com
  Target Milestone: ---

p/P followed by +/- is not part of the pp-number production in C++ before
C++17, but GCC includes them anyway. This results in the following code being
erroneously rejected in C++11/14 mode:

long double operator""_p(long double) { return {}; }
auto x = 0e1_p+0; // should be parsed as 0e1_p + 0
                  // but parsed as a single pp-number instead and rejected