doxygen: replace DEAL_II_CONSTEXPR

Documentation looks a bit funny with this macro, but it should be safe
to replace with ``constexpr``.

diff --git a/doc/doxygen/options.dox.in b/doc/doxygen/options.dox.in
index e55419c9b6e7ced2d4e80468460e894d2af3f13a..ec652fb8fa96d0660e74233c0e30f017395decaa 100644 (file)
--- a/doc/doxygen/options.dox.in
+++ b/doc/doxygen/options.dox.in
@@ -210,6 +210,7 @@ PREDEFINED             = DOXYGEN=1 \
                          DEAL_II_TRILINOS_WITH_ROL=1 \
                          DEAL_II_WITH_UMFPACK=1 \
                          DEAL_II_WITH_ZLIB=1 \
+                         DEAL_II_CONSTEXPR=constexpr \
                          DEAL_II_NAMESPACE_OPEN= \
                          DEAL_II_NAMESPACE_CLOSE= \
                          DEAL_II_ENABLE_EXTRA_DIAGNOSTICS= \