From: Wolfgang Bangerth <bangerth@colostate.edu>
Date: Tue, 20 Jun 2023 18:02:47 +0000 (-0600)
Subject: Try to work around an Intel compiler issue.
X-Git-Tag: v9.5.0-rc1~66^2~1
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f86ac4236738fc9a8b55066fcd4ca16c7f2a8a9c;p=dealii.git

Try to work around an Intel compiler issue.
---

diff --git a/source/dofs/dof_handler_policy.cc b/source/dofs/dof_handler_policy.cc
index f4519e50c1..8dd4147212 100644
--- a/source/dofs/dof_handler_policy.cc
+++ b/source/dofs/dof_handler_policy.cc
@@ -3529,14 +3529,18 @@ namespace internal
               cell->active_fe_index(),
               DoFAccessorImplementation::Implementation::
                 DoFIndexProcessor<dim, spacedim>(),
-              [&complete](auto &stored_index, auto received_index) {
-                if (*received_index != numbers::invalid_dof_index)
+
+              // Intel ICC 19 and earlier for some reason believe that
+              // numbers::invalid_dof_index is not a valid object
+              // inside the lambda function. Fix this by creating a
+              // local variable initialized by the global one.
+              [&complete, invalid_dof_index = numbers::invalid_dof_index](
+                auto &stored_index, const auto received_index) {
+                if (*received_index != invalid_dof_index)
                   {
-#    if !defined(__INTEL_COMPILER) || __INTEL_COMPILER >= 1900
-                    Assert((stored_index == (numbers::invalid_dof_index)) ||
+                    Assert((stored_index == (invalid_dof_index)) ||
                              (stored_index == *received_index),
                            ExcInternalError());
-#    endif
                     stored_index = *received_index;
                   }
                 else