fixup: remove class lambdas; use local copies + class operators

.github/workflows/CI.yml

@@ -57,7 +57,6 @@ jobs:
             -DCMAKE_BUILD_TYPE=${{ matrix.cmake_build_type }} \
             -DCMAKE_CXX_COMPILER=${{ matrix.cxx }} \
             -DCMAKE_INSTALL_PREFIX=$HOME/kokkos \
-            -DCMAKE_CXX_STANDARD=20 \
             -DKokkos_ENABLE_${{ matrix.backend }}=ON \
             -DKokkos_ENABLE_HWLOC=ON
           cmake --build build --parallel 2
@@ -149,7 +148,6 @@ jobs:
         run: |
           cmake -B build \
             -DCMAKE_INSTALL_PREFIX=$HOME/kokkos \
-            -DCMAKE_CXX_STANDARD=20 \
             -DKokkos_ENABLE_HIP=ON \
             -DKokkos_ARCH_VEGA908=ON \
             -DCMAKE_BUILD_TYPE=${{ matrix.cmake_build_type }} \
@@ -232,7 +230,6 @@ jobs:
         run: |
           cmake -B build \
             -DCMAKE_INSTALL_PREFIX=$HOME/kokkos \
-            -DCMAKE_CXX_STANDARD=20 \
             -DKokkos_ENABLE_CUDA=ON \
             -DKokkos_ARCH_VOLTA72=ON \
             -DKokkos_ENABLE_CUDA_LAMBDA=ON \

src/CabanaPD_ForceModels.hpp

@@ -65,11 +65,12 @@ struct BaseForceModel
         , num_types( _delta.size() )
     {
         max_delta = 0;
-        auto init_func = KOKKOS_CLASS_LAMBDA( const int i, double& max )
+        auto delta_copy = delta;
+        auto init_func = KOKKOS_LAMBDA( const int i, double& max )
         {
-            delta( i ) = _delta[i];
-            if ( delta( i ) > max )
-                max = delta( i );
+            delta_copy( i ) = _delta[i];
+            if ( delta_copy( i ) > max )
+                max = delta_copy( i );
         };
         using exec_space = typename memory_space::execution_space;
         Kokkos::RangePolicy<exec_space> policy( 0, num_types );
@@ -138,10 +139,12 @@ struct BaseTemperatureModel
         , temperature( _temp )
         , type( _type )
     {
-        auto init_func = KOKKOS_CLASS_LAMBDA( const int i )
+        auto alpha_copy = alpha;
+        auto temp0_copy = temp0;
+        auto init_func = KOKKOS_LAMBDA( const int i )
         {
-            alpha( i ) = _alpha[i];
-            temp0( i ) = _temp0[i];
+            alpha_copy( i ) = _alpha[i];
+            temp0_copy( i ) = _temp0[i];
         };
         using exec_space = typename memory_space::execution_space;
         Kokkos::RangePolicy<exec_space> policy( 0, alpha.size() );

src/force/CabanaPD_ForceModels_PMB.hpp

@@ -91,25 +91,30 @@ struct ForceModel<PMB, Elastic, TemperatureIndependent, ParticleType>
     template <typename ArrayType>
     void setParameters( const ArrayType& _K )
     {
-        // Initialize self interaction parameters.
-        auto init_self_func = KOKKOS_CLASS_LAMBDA( const int i )
+        // Initialize per-type variables.
+        auto K_copy = K;
+        auto init_self_func = KOKKOS_LAMBDA( const int i )
         {
-            K( i ) = _K[i];
-            c( i, i ) = micromodulus( i );
+            K_copy( i ) = _K[i];
         };
         using exec_space = typename memory_space::execution_space;
         Kokkos::RangePolicy<exec_space> policy( 0, num_types );
-        Kokkos::parallel_for( "CabanaPD::Model::Init", policy, init_self_func );
+        Kokkos::parallel_for( "CabanaPD::Model::Copy", policy, init_self_func );
         Kokkos::fence();
 
-        // Initialize cross-terms.
-        auto init_cross_func = KOKKOS_CLASS_LAMBDA( const int i )
+        // Initialize model parameters.
+        Kokkos::parallel_for( "CabanaPD::Model::Init", policy, *this );
+    }
+
+    KOKKOS_INLINE_FUNCTION void operator()( const int i ) const
+    {
+        c( i, i ) = micromodulus( i );
+        for ( std::size_t j = i; j < num_types; j++ )
         {
-            for ( std::size_t j = i; j < num_types; j++ )
-                c( i, j ) = ( micromodulus( i ) + micromodulus( j ) ) / 2.0;
-        };
-        Kokkos::parallel_for( "CabanaPD::Model::Init", policy,
-                              init_cross_func );
+            c( i, j ) = ( micromodulus( i ) + micromodulus( j ) ) / 2.0;
+            // Set symmetric cross-terms.
+            c( j, i ) = c( i, j );
+        }
     }
 
     KOKKOS_INLINE_FUNCTION
@@ -217,31 +222,35 @@ struct ForceModel<PMB, Fracture, TemperatureIndependent, ParticleType>
     template <typename ArrayType>
     void setParameters( const ArrayType& _G0 )
     {
-        // Initialize self interaction parameters.
-        auto init_self_func = KOKKOS_CLASS_LAMBDA( const int i )
+        // Initialize per-type variables.
+        auto G0_copy = G0;
+        auto init_self_func = KOKKOS_LAMBDA( const int i )
         {
-            G0( i ) = _G0[i];
-            s0( i, i ) = criticalStretch( i );
-            bond_break_coeff( i, i ) =
-                ( 1.0 + s0( i, i ) ) * ( 1.0 + s0( i, i ) );
+            G0_copy( i ) = _G0[i];
         };
         using exec_space = typename memory_space::execution_space;
         Kokkos::RangePolicy<exec_space> policy( 0, num_types );
         Kokkos::parallel_for( "CabanaPD::Model::Init", policy, init_self_func );
         Kokkos::fence();
 
         // Initialize cross-terms.
-        auto init_cross_func = KOKKOS_CLASS_LAMBDA( const int i )
+        Kokkos::parallel_for( "CabanaPD::Model::Init", policy, *this );
+    }
+
+    KOKKOS_INLINE_FUNCTION void operator()( const int i ) const
+    {
+        s0( i, i ) = criticalStretch( i );
+        bond_break_coeff( i, i ) = ( 1.0 + s0( i, i ) ) * ( 1.0 + s0( i, i ) );
+
+        for ( std::size_t j = i; j < num_types; j++ )
         {
-            for ( std::size_t j = i; j < num_types; j++ )
-            {
-                s0( i, j ) = criticalStretch( i, j );
-                bond_break_coeff( i, j ) =
-                    ( 1.0 + s0( i, j ) ) * ( 1.0 + s0( i, j ) );
-            }
-        };
-        Kokkos::parallel_for( "CabanaPD::Model::Init", policy,
-                              init_cross_func );
+            s0( i, j ) = criticalStretch( i, j );
+            bond_break_coeff( i, j ) =
+                ( 1.0 + s0( i, j ) ) * ( 1.0 + s0( i, j ) );
+            // Set symmetric cross-terms.
+            s0( j, i ) = s0( i, j );
+            bond_break_coeff( j, i ) = bond_break_coeff( i, j );
+        }
     }
 
     KOKKOS_INLINE_FUNCTION