[Bug c++/81853] [ 6/7/8 Regression] "using namespace" is not a constant expression in a statement expression

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81853

--- Comment #3 from Jason Merrill <jason at gcc dot gnu.org> ---
Author: jason
Date: Fri Feb 16 21:06:50 2018
New Revision: 257766

URL: https://gcc.gnu.org/viewcvs?rev=257766&root=gcc&view=rev
Log:
        PR c++/81853 - using-directive and constexpr.

        * constexpr.c (cxx_eval_constant_expression): Handle USING_STMT.

Added:
    branches/gcc-7-branch/gcc/testsuite/g++.dg/ext/stmtexpr22.C
Modified:
    branches/gcc-7-branch/gcc/cp/ChangeLog
    branches/gcc-7-branch/gcc/cp/constexpr.c