From d8bece774e16123d658228b7116a40ce3ba97af3 Mon Sep 17 00:00:00 2001
From: Marc Fehling <mafehling.git@gmail.com>
Date: Mon, 5 Jun 2023 20:43:16 -0600
Subject: [PATCH] Use numbers::is_finite whenever we compare with infinity.

---
 include/deal.II/lac/utilities.h      |  2 +-
 source/fe/mapping_q.cc               | 13 ++++++-------
 source/particles/particle_handler.cc |  8 ++++----
 3 files changed, 11 insertions(+), 12 deletions(-)

diff --git a/include/deal.II/lac/utilities.h b/include/deal.II/lac/utilities.h
index 1e91f3623f..058aaf5b69 100644
--- a/include/deal.II/lac/utilities.h
+++ b/include/deal.II/lac/utilities.h
@@ -432,7 +432,7 @@ namespace Utilities
       const double b = unwanted_spectrum.second;
       Assert(degree > 0, ExcMessage("Only positive degrees make sense."));
 
-      const bool scale = (a_L < std::numeric_limits<double>::infinity());
+      const bool scale = numbers::is_finite(a_L);
       Assert(
         a < b,
         ExcMessage(
diff --git a/source/fe/mapping_q.cc b/source/fe/mapping_q.cc
index 7d0f7472ff..527004b332 100644
--- a/source/fe/mapping_q.cc
+++ b/source/fe/mapping_q.cc
@@ -580,9 +580,8 @@ MappingQ<dim, spacedim>::transform_real_to_unit_cell(
   // statement may throw an exception, which we simply pass up to the caller
   const Point<dim> p_unit =
     this->transform_real_to_unit_cell_internal(cell, p, initial_p_unit);
-  if (p_unit[0] == std::numeric_limits<double>::infinity())
-    AssertThrow(false,
-                (typename Mapping<dim, spacedim>::ExcTransformationFailed()));
+  AssertThrow(numbers::is_finite(p_unit[0]),
+              (typename Mapping<dim, spacedim>::ExcTransformationFailed()));
   return p_unit;
 }
 
@@ -646,7 +645,10 @@ MappingQ<dim, spacedim>::transform_points_real_to_unit_cell(
         // determinants) from other SIMD lanes. Repeat the computation in this
         // unlikely case with scalar arguments.
         for (unsigned int j = 0; j < n_lanes && i + j < n_points; ++j)
-          if (unit_point[0][j] == std::numeric_limits<double>::infinity())
+          if (numbers::is_finite(unit_point[0][j]))
+            for (unsigned int d = 0; d < dim; ++d)
+              unit_points[i + j][d] = unit_point[d][j];
+          else
             unit_points[i + j] = internal::MappingQImplementation::
               do_transform_real_to_unit_cell_internal<dim, spacedim>(
                 real_points[i + j],
@@ -654,9 +656,6 @@ MappingQ<dim, spacedim>::transform_points_real_to_unit_cell(
                 support_points,
                 polynomials_1d,
                 renumber_lexicographic_to_hierarchic);
-          else
-            for (unsigned int d = 0; d < dim; ++d)
-              unit_points[i + j][d] = unit_point[d][j];
       }
     else
       unit_points[i] = internal::MappingQImplementation::
diff --git a/source/particles/particle_handler.cc b/source/particles/particle_handler.cc
index 0bc71a019d..6f46f472df 100644
--- a/source/particles/particle_handler.cc
+++ b/source/particles/particle_handler.cc
@@ -1261,11 +1261,11 @@ namespace Particles
         auto particle = pic.begin();
         for (const auto &p_unit : reference_locations)
           {
-            if (p_unit[0] == std::numeric_limits<double>::infinity() ||
-                !GeometryInfo<dim>::is_inside_unit_cell(p_unit))
-              particles_out_of_cell.push_back(particle);
-            else
+            if (numbers::is_finite(p_unit[0]) &&
+                GeometryInfo<dim>::is_inside_unit_cell(p_unit))
               particle->set_reference_location(p_unit);
+            else
+              particles_out_of_cell.push_back(particle);
 
             ++particle;
           }
-- 
2.39.5