From ac94066b1983e8d73363cf59842dd590a6182b56 Mon Sep 17 00:00:00 2001
From: Wolfgang Bangerth <bangerth@colostate.edu>
Date: Wed, 8 Mar 2023 19:55:53 -0700
Subject: [PATCH] Let doxygen know how to handle 'requires' expressions.

---
 doc/doxygen/options.dox.in | 1 +
 1 file changed, 1 insertion(+)

diff --git a/doc/doxygen/options.dox.in b/doc/doxygen/options.dox.in
index b95298ffa2..045d5d88b7 100644
--- a/doc/doxygen/options.dox.in
+++ b/doc/doxygen/options.dox.in
@@ -184,6 +184,7 @@ PREDEFINED             = DOXYGEN=1 \
                          DEAL_II_HOST_DEVICE= \
                          DEAL_II_ALWAYS_INLINE= \
                          __device__= \
+			 DEAL_II_CXX20_REQUIRES=requires \
                          DEAL_II_WITH_ADOLC=1 \
                          DEAL_II_ADOLC_WITH_ADVANCED_BRANCHING=1 \
                          DEAL_II_ADOLC_WITH_ATRIG_ERF=1 \
-- 
2.39.5