add cache accessor for private member to test

Author: yhmtsai

core/base/dense_cache.cpp

@@ -12,6 +12,7 @@
 #include <ginkgo/core/base/executor.hpp>
 #include <ginkgo/core/matrix/dense.hpp>
 
+#include "core/base/dense_cache_accessor.hpp"
 
 namespace gko {
 namespace detail {
@@ -38,6 +39,13 @@ void DenseCache<ValueType>::init_from(
 }
 
 
+const array<char>& GenericDenseCacheAccessor::get_workspace(
+    const GenericDenseCache& cache)
+{
+    return cache.workspace;
+}
+
+
 GenericDenseCache::GenericDenseCache(const GenericDenseCache&) {}
 
 
@@ -76,6 +84,26 @@ std::shared_ptr<matrix::Dense<ValueType>> GenericDenseCache::get(
 }
 
 
+std::shared_ptr<const Executor> ScalarCacheAccessor::get_executor(
+    const ScalarCache& cache)
+{
+    return cache.exec;
+}
+
+
+double ScalarCacheAccessor::get_value(const ScalarCache& cache)
+{
+    return cache.value;
+}
+
+
+const std::map<std::string, std::shared_ptr<const gko::LinOp>>&
+ScalarCacheAccessor::get_scalars(const ScalarCache& cache)
+{
+    return cache.scalars;
+}
+
+
 ScalarCache::ScalarCache(std::shared_ptr<const Executor> executor,
                          double scalar_value)
     : exec(std::move(executor)), value(scalar_value){};

core/base/dense_cache_accessor.hpp

@@ -0,0 +1,51 @@
+// SPDX-FileCopyrightText: 2025 The Ginkgo authors
+//
+// SPDX-License-Identifier: BSD-3-Clause
+
+#ifndef GKO_CORE_BASE_DENSE_CACHE_ACCESSOR_HPP_
+#define GKO_CORE_BASE_DENSE_CACHE_ACCESSOR_HPP_
+
+
+#include <iostream>
+#include <map>
+#include <string>
+
+#include <ginkgo/core/base/array.hpp>
+#include <ginkgo/core/base/dense_cache.hpp>
+#include <ginkgo/core/base/executor.hpp>
+#include <ginkgo/core/base/lin_op.hpp>
+
+
+namespace gko {
+namespace detail {
+
+
+// helper to access private member for testing
+class GenericDenseCacheAccessor {
+public:
+    // access to the workspace
+    static const array<char>& get_workspace(const GenericDenseCache& cache);
+};
+
+
+// helper to access private member for testing
+class ScalarCacheAccessor {
+public:
+    // access to the executor
+    static std::shared_ptr<const Executor> get_executor(
+        const ScalarCache& cache);
+
+    // access to the value
+    static double get_value(const ScalarCache& cache);
+
+    // access to the scalars
+    static const std::map<std::string, std::shared_ptr<const gko::LinOp>>&
+    get_scalars(const ScalarCache& cache);
+};
+
+
+}  // namespace detail
+}  // namespace gko
+
+
+#endif  // GKO_CORE_BASE_DENSE_CACHE_ACCESSOR_HPP_