Merge pull request #12749 from bangerth/size_type

Consistently declare size_type in preconditioners derived from PreconditionRelaxation.

include/deal.II/lac/precondition.h

@@ -497,6 +497,11 @@ template <typename MatrixType = SparseMatrix<double>>
 class PreconditionJacobi : public PreconditionRelaxation<MatrixType>
 {
 public:
+  /**
+   * Declare type for container size.
+   */
+  using size_type = typename PreconditionRelaxation<MatrixType>::size_type;
+
   /**
    * An alias to the base class AdditionalData.
    */
@@ -583,6 +588,11 @@ template <typename MatrixType = SparseMatrix<double>>
 class PreconditionSOR : public PreconditionRelaxation<MatrixType>
 {
 public:
+  /**
+   * Declare type for container size.
+   */
+  using size_type = typename PreconditionRelaxation<MatrixType>::size_type;
+
   /**
    * An alias to the base class AdditionalData.
    */
@@ -651,15 +661,15 @@ class PreconditionSSOR : public PreconditionRelaxation<MatrixType>
 {
 public:
   /**
-   * An alias to the base class AdditionalData.
+   * Declare type for container size.
    */
-  using AdditionalData =
-    typename PreconditionRelaxation<MatrixType>::AdditionalData;
+  using size_type = typename PreconditionRelaxation<MatrixType>::size_type;
 
   /**
-   * Declare type for container size.
+   * An alias to the base class AdditionalData.
    */
-  using size_type = typename MatrixType::size_type;
+  using AdditionalData =
+    typename PreconditionRelaxation<MatrixType>::AdditionalData;
 
   /**
    * An alias to the base class.
@@ -752,7 +762,7 @@ class PreconditionPSOR : public PreconditionRelaxation<MatrixType>
   /**
    * Declare type for container size.
    */
-  using size_type = typename MatrixType::size_type;
+  using size_type = typename PreconditionRelaxation<MatrixType>::size_type;
 
   /**
    * Parameters for PreconditionPSOR.