Add a few missing assertions

Note that some of them were already set by Kokkos (in debug mode), but
it seems better to only rely on `pugs` definitions

src/algebra/SparseMatrixDescriptor.hpp

@@ -28,14 +28,16 @@ class SparseMatrixDescriptor
       return m_id_value_map.size();
     }
 
-    const DataType& operator[](const IndexType& j) const
+    const DataType&
+    operator[](const IndexType& j) const
     {
       auto i_value = m_id_value_map.find(j);
       Assert(i_value != m_id_value_map.end());
       return i_value->second;
     }
 
-    DataType& operator[](const IndexType& j)
+    DataType&
+    operator[](const IndexType& j)
     {
       auto i_value = m_id_value_map.find(j);
       if (i_value != m_id_value_map.end()) {
@@ -51,7 +53,7 @@ class SparseMatrixDescriptor
     operator<<(std::ostream& os, const SparseRowDescriptor& row)
     {
       for (auto [j, value] : row.m_id_value_map) {
-        os << ' ' << j << ':' << value;
+        os << ' ' << static_cast<size_t>(j) << ':' << value;
       }
       return os;
     }
@@ -73,24 +75,30 @@ class SparseMatrixDescriptor
   SparseRowDescriptor&
   row(const IndexType i)
   {
+    Assert(i < m_row_array.size());
     return m_row_array[i];
   }
 
   const SparseRowDescriptor&
   row(const IndexType i) const
   {
+    Assert(i < m_row_array.size());
     return m_row_array[i];
   }
 
   DataType&
   operator()(const IndexType& i, const IndexType& j)
   {
+    Assert(i < m_row_array.size());
+    Assert(j < m_row_array.size());
     return m_row_array[i][j];
   }
 
   const DataType&
   operator()(const IndexType& i, const IndexType& j) const
   {
+    Assert(i < m_row_array.size());
+    Assert(j < m_row_array.size());
     const auto& r = m_row_array[i];   // split to ensure const-ness of call
     return r[j];
   }
@@ -99,7 +107,7 @@ class SparseMatrixDescriptor
   operator<<(std::ostream& os, const SparseMatrixDescriptor& M)
   {
     for (IndexType i = 0; i < M.m_row_array.size(); ++i) {
-      os << i << " |" << M.m_row_array[i] << '\n';
+      os << static_cast<size_t>(i) << " |" << M.m_row_array[i] << '\n';
     }
     return os;
   }

src/mesh/ItemToItemMatrix.hpp

@@ -29,8 +29,10 @@ class ItemToItemMatrix
     }
 
     PUGS_INLINE
-    TargetItemId operator[](size_t j) const
+    TargetItemId
+    operator[](size_t j) const
     {
+      Assert(j < m_row.length);
       return m_row(j);
     }
 
@@ -73,15 +75,19 @@ class ItemToItemMatrix
   }
 
   PUGS_INLINE
-  auto operator[](const SourceItemId& source_id) const
+  auto
+  operator[](const SourceItemId& source_id) const
   {
+    Assert(source_id < m_connectivity_matrix.numRows());
     using RowType = decltype(m_connectivity_matrix.rowConst(source_id));
     return SubItemList<RowType>(m_connectivity_matrix.rowConst(source_id));
   }
 
   template <typename IndexType>
-  PUGS_INLINE const auto& operator[](const IndexType& source_id) const
+  PUGS_INLINE const auto&
+  operator[](const IndexType& source_id) const
   {
+    Assert(source_id < m_connectivity_matrix.numRows());
     static_assert(std::is_same_v<IndexType, SourceItemId>, "ItemToItemMatrix must be indexed using correct ItemId");
     using RowType = decltype(m_connectivity_matrix.rowConst(source_id));
     return SubItemList<RowType>(m_connectivity_matrix.rowConst(source_id));

tests/test_SparseMatrixDescriptor.cpp

@@ -168,4 +168,30 @@ TEST_CASE("SparseMatrixDescriptor", "[algebra]")
     REQUIRE(value_array[6] == 1);
     REQUIRE(value_array[7] == -2);
   }
+
+  SECTION("output")
+  {
+    SparseMatrixDescriptor<int, uint8_t> S{5};
+    S(0, 2) = 3;
+    S(1, 2) = 11;
+    S(1, 1) = 1;
+    S(0, 2) += 2;
+    S(3, 3) = 5;
+    S(3, 1) = -3;
+    S(4, 1) = 1;
+    S(2, 2) = 4;
+    S(4, 4) = -2;
+
+    std::ostringstream output;
+    output << '\n' << S;
+
+    std::string expected_output = R"(
+0 | 2:5
+1 | 1:1 2:11
+2 | 2:4
+3 | 1:-3 3:5
+4 | 1:1 4:-2
+)";
+    REQUIRE(output.str() == expected_output);
+  }
 }