Feat/cmd simple usages

README.md

@@ -103,6 +103,41 @@ int main()
 }
 ```
 
+### `cmd::CommandHistory` example
+
+```cpp
+import std;
+import cmd;
+
+imt main()
+{
+    cmd::CommandHistory history;
+	cmd::Context<int> ctx;
+
+    try
+    {
+        history.Execute(std::make_unique<cmd::Insert<int>>(ctx, 0, 10));
+    }
+    catch(const std::out_of_range &e)
+    {
+        std::println("Error: {}", e.what());
+        return 0;
+    }
+
+	if (history.CanUndo())
+	{
+		history.Undo();
+	}
+
+	if (history.CanRedo())
+	{
+		history.Redo();
+	}
+
+    return 0;
+}
+```
+
 ## TODO
 
 ### Input

command/src/CommandInsert.cppm

@@ -17,7 +17,7 @@ export namespace cmd
 	public:
 		Insert(Context<ContextT> &ctx, std::size_t index, ContextT value) : _ctx(ctx), _index(index), _value(std::move(value))
 		{
-			if (index >= ctx.data.size())
+			if ((index >= ctx.data.size()) && (_index != 0))
 			{
 				throw std::out_of_range("cmd::Insert: index out of range");
 			}

command/src/ICommand.cppm

@@ -1,27 +1,30 @@
-module cmd:ICommand;
+export module cmd:ICommand;
 
 import std;
 
-template <typename ContextT>
-struct Context
+export namespace cmd
 {
-    std::vector<ContextT> data;
-};
+    template <typename ContextT>
+    struct Context
+    {
+        std::vector<ContextT> data;
+    };
 
-class ICommand
-{
-protected:
-    ICommand() = default;
+    class ICommand
+    {
+    protected:
+        ICommand() = default;
 
-public:
-    virtual ~ICommand() = default;
+    public:
+        virtual ~ICommand() = default;
 
-    ICommand(const ICommand &) = delete;
-    ICommand(ICommand &&) = delete;
-    ICommand &operator=(const ICommand &) = delete;
-    ICommand &operator=(ICommand &&) = delete;
+        ICommand(const ICommand &) = delete;
+        ICommand(ICommand &&) = delete;
+        ICommand &operator=(const ICommand &) = delete;
+        ICommand &operator=(ICommand &&) = delete;
 
-    virtual void Execute() = 0;
-    virtual void Undo() = 0;
-    [[nodiscard]] virtual std::string Description() const = 0;
+        virtual void Execute() = 0;
+        virtual void Undo() = 0;
+        [[nodiscard]] virtual std::string Description() const = 0;
+    };
 };

command/src/cmd.cppm

@@ -1,7 +1,6 @@
 export module cmd;
 
-import :ICommand;
-
+export import :ICommand;
 export import :CommandClear;
 export import :CommandErase;
 export import :CommandHistory;