Allows components to remove a child by index.

include/ftxui/component/component_base.hpp

@@ -29,7 +29,7 @@ class ComponentBase {
   // ComponentBase hierarchy.
   ComponentBase* Parent();
   void Add(Component children);
-
+  void Remove(std::size_t idx);
   // Renders the component.
   virtual Element Render();
 

src/ftxui/component/component.cpp

@@ -41,6 +41,13 @@ void ComponentBase::Add(Component child) {
   children_.push_back(std::move(child));
 }
 
+/// @brief Remove a child.
+/// @@param idx The child index to be removed.
+/// @ingroup component
+void ComponentBase::Remove(std::size_t idx) {
+  children_.erase(children_.begin()+idx);
+}
+
 /// @brief Draw the component.
 /// Build a ftxui::Element to be drawn on the ftxi::Screen representing this
 /// ftxui::ComponentBase.