Add foundation

Toolkit.Foundation/ICache.cs

@@ -0,0 +1,30 @@
+namespace Toolkit.Foundation;
+
+public interface ICache<TValue> :
+    IEnumerable<TValue>
+{
+    void Add(TValue value);
+
+    void Clear();
+
+    bool Remove(TValue value);
+}
+
+public interface ICache<TKey, TValue> :
+    IEnumerable<KeyValuePair<TKey, TValue>>
+    where TKey :
+    notnull
+    where TValue : 
+    notnull
+{
+    void Add(TKey key, 
+        TValue value);
+
+    void Clear();
+
+    bool ContainsKey(TKey key);
+
+    bool Remove(TKey key);
+
+    bool TryGetValue(TKey key, out TValue? value);
+}