[Bug c++/83873] New: adjacent digit separators are accepted in the exponent-part of floating-point literals

[smw at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83873

            Bug ID: 83873
           Summary: adjacent digit separators are accepted in the
                    exponent-part of floating-point literals
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: smw at gcc dot gnu.org
  Target Milestone: ---

GCC diagnoses adjacent digit separators in integral literals and the
fractional-constant of floating point literals (as it should, according to the
productions in the grammar) but accepts an arbitrary number of adjacent digit
separators in the exponent-part of floating-point literals.

An example might speak volumes.

  long double f = 1.0e1'''''''0;

Boom: clean compile.