Add std::string_view to ConstStringRef

include/ftxui/util/ref.hpp

@@ -18,8 +18,13 @@ template <typename T>
 class ConstRef {
  public:
   ConstRef() = default;
+
+  // Owning constructors:
   ConstRef(T t) : variant_(std::move(t)) {}  // NOLINT
+
+  // Referencing constructors:
   ConstRef(const T* t) : variant_(t) {}      // NOLINT
+
   ConstRef& operator=(ConstRef&&) noexcept = default;
   ConstRef(const ConstRef<T>&) = default;
   ConstRef(ConstRef<T>&&) noexcept = default;
@@ -47,8 +52,13 @@ template <typename T>
 class Ref {
  public:
   Ref() = default;
+
+  // Owning constructors:
   Ref(T t) : variant_(std::move(t)) {}  // NOLINT
+                                        //
+  // Referencing constructors:
   Ref(T* t) : variant_(t) {}            // NOLINT
+                                        //
   ~Ref() = default;
   Ref& operator=(Ref&&) noexcept = default;
   Ref(const Ref<T>&) = default;
@@ -84,10 +94,15 @@ class StringRef : public Ref<std::string> {
  public:
   using Ref<std::string>::Ref;
 
+  // Owning constructors:
   StringRef(const wchar_t* ref)  // NOLINT
       : StringRef(to_string(std::wstring(ref))) {}
   StringRef(const char* ref)  // NOLINT
       : StringRef(std::string(ref)) {}
+  StringRef(std::string_view ref)  // NOLINT
+      : StringRef(std::string(ref)) {}
+  StringRef(std::wstring_view ref)  // NOLINT
+      : StringRef(to_string(ref)) {}
 };
 
 /// @brief An adapter. Own or reference a constant string. For convenience, this
@@ -96,14 +111,21 @@ class ConstStringRef : public ConstRef<std::string> {
  public:
   using ConstRef<std::string>::ConstRef;
 
+  // Referencing constructors:
   ConstStringRef(const std::wstring* ref)  // NOLINT
       : ConstStringRef(to_string(*ref)) {}
+
+  // Owning constructors:
   ConstStringRef(const std::wstring ref)  // NOLINT
       : ConstStringRef(to_string(ref)) {}
+  ConstStringRef(std::wstring_view ref)  // NOLINT
+      : ConstStringRef(to_string(ref)) {}
   ConstStringRef(const wchar_t* ref)  // NOLINT
       : ConstStringRef(to_string(std::wstring(ref))) {}
   ConstStringRef(const char* ref)  // NOLINT
       : ConstStringRef(std::string(ref)) {}
+  ConstStringRef(std::string_view ref)  // NOLINT
+      : ConstStringRef(std::string(ref)) {}
 };
 
 /// @brief An adapter. Reference a list of strings.
@@ -144,33 +166,26 @@ class ConstStringListRef {
   ConstStringListRef(ConstStringListRef&&) = default;
   ConstStringListRef(const ConstStringListRef&) = default;
 
-  ConstStringListRef(std::vector<std::string> value)  // NOLINT
+  ConstStringListRef(std::vector<std::string> value) {  // NOLINT
-  {
     variant_ = std::make_shared<Variant>(value);
   }
-  ConstStringListRef(const std::vector<std::string>* value)  // NOLINT
+  ConstStringListRef(const std::vector<std::string>* value)  {// NOLINT
-  {
     variant_ = std::make_shared<Variant>(value);
   }
-  ConstStringListRef(std::vector<std::string_view> value)  // NOLINT
+  ConstStringListRef(std::vector<std::string_view> value) { // NOLINT
-  {
     variant_ = std::make_shared<Variant>(value);
   }
-  ConstStringListRef(const std::vector<std::string_view>* value)  // NOLINT
+  ConstStringListRef(const std::vector<std::string_view>* value) { // NOLINT
-  {
     variant_ = std::make_shared<Variant>(value);
   }
-  ConstStringListRef(const std::vector<std::wstring>* value)  // NOLINT
+  ConstStringListRef(const std::vector<std::wstring>* value) { // NOLINT
-  {
     variant_ = std::make_shared<Variant>(value);
   }
-  ConstStringListRef(Adapter* adapter)  // NOLINT
+  ConstStringListRef(Adapter* adapter) { // NOLINT
-  {
     variant_ = std::make_shared<Variant>(adapter);
   }
   template <typename AdapterType>
-  ConstStringListRef(std::unique_ptr<AdapterType> adapter)  // NOLINT
+  ConstStringListRef(std::unique_ptr<AdapterType> adapter) {  // NOLINT
-  {
     variant_ = std::make_shared<Variant>(
         static_cast<std::unique_ptr<Adapter>>(std::move(adapter)));
   }
@@ -179,66 +194,34 @@ class ConstStringListRef {
     return variant_ ? std::visit(SizeVisitor(), *variant_) : 0;
   }
 
-  std::string operator[](size_t i) const {
+  std::string_view operator[](size_t i) const {
-    if (!variant_) {
+    return variant_ ? std::visit(IndexedGetter{i}, *variant_) : "";
-      return "";
-    }
-    auto& v = *variant_;
-    if (std::holds_alternative<const std::vector<std::string>>(v)) {
-      return std::get<const std::vector<std::string>>(v)[i];
-    }
-    if (std::holds_alternative<const std::vector<std::string>*>(v)) {
-      return (*std::get<const std::vector<std::string>*>(v))[i];
-    }
-    if (std::holds_alternative<const std::vector<std::string_view>>(v)) {
-      return std::string(std::get<const std::vector<std::string_view>>(v)[i]);
-    }
-    if (std::holds_alternative<const std::vector<std::string_view>*>(v)) {
-      return std::string(
-          (*std::get<const std::vector<std::string_view>*>(v))[i]);
-    }
-    if (std::holds_alternative<const std::vector<std::wstring>*>(v)) {
-      return to_string((*std::get<const std::vector<std::wstring>*>(v))[i]);
-    }
-    if (std::holds_alternative<Adapter*>(v)) {
-      return std::string((*std::get<Adapter*>(v))[i]);
-    }
-    if (std::holds_alternative<std::unique_ptr<Adapter>>(v)) {
-      return std::string((*std::get<std::unique_ptr<Adapter>>(v))[i]);
-    }
-    return "";
-  }
-
-  std::string_view at(size_t i) const {
-    if (!variant_) {
-      return "";
-    }
-    auto& v = *variant_;
-    if (std::holds_alternative<const std::vector<std::string>>(v)) {
-      return std::get<const std::vector<std::string>>(v)[i];
-    }
-    if (std::holds_alternative<const std::vector<std::string>*>(v)) {
-      return (*std::get<const std::vector<std::string>*>(v))[i];
-    }
-    if (std::holds_alternative<const std::vector<std::string_view>>(v)) {
-      return std::get<const std::vector<std::string_view>>(v)[i];
-    }
-    if (std::holds_alternative<const std::vector<std::string_view>*>(v)) {
-      return (*std::get<const std::vector<std::string_view>*>(v))[i];
-    }
-    if (std::holds_alternative<const std::vector<std::wstring>*>(v)) {
-      return {};
-    }
-    if (std::holds_alternative<Adapter*>(v)) {
-      return (*std::get<Adapter*>(v))[i];
-    }
-    if (std::holds_alternative<std::unique_ptr<Adapter>>(v)) {
-      return (*std::get<std::unique_ptr<Adapter>>(v))[i];
-    }
-    return {};
   }
 
  private:
+  struct IndexedGetter {
+    size_t i;
+    std::string_view operator()(const std::vector<std::string>& v) const {
+      return v[i];
+    }
+    std::string_view operator()(const std::vector<std::string>* v) const {
+      return (*v)[i];
+    }
+    std::string_view operator()(const std::vector<std::string_view>& v) const {
+      return std::string(v[i]);
+    }
+    std::string_view operator()(const std::vector<std::string_view>* v) const {
+      return std::string((*v)[i]);
+    }
+    std::string_view operator()(const std::vector<std::wstring>* v) const {
+      return to_string((*v)[i]);
+    }
+    std::string_view operator()(Adapter* v) const { return std::string((*v)[i]); }
+    std::string_view operator()(const std::unique_ptr<Adapter>& v) const {
+      return (*v)[i];
+    }
+  };
+
   struct SizeVisitor {
     size_t operator()(const std::vector<std::string>& v) const {
       return v.size();

src/ftxui/component/menu.cpp

@@ -123,7 +123,7 @@ class MenuBase : public ComponentBase, public MenuOption {
       const bool is_selected = (selected() == i);
 
       const EntryState state = {
-          entries[i], false, is_selected, is_focused, i,
+        std::string(entries[i]), false, is_selected, is_focused, i,
       };
 
       Element element = (entries_option.transform ? entries_option.transform

src/ftxui/component/radiobox.cpp

@@ -37,7 +37,7 @@ class RadioboxBase : public ComponentBase, public RadioboxOption {
       const bool is_focused = (focused_entry() == i) && is_menu_focused;
       const bool is_selected = (hovered_ == i);
       auto state = EntryState{
-          entries[i], selected() == i, is_selected, is_focused, i,
+          std::string(entries[i]), selected() == i, is_selected, is_focused, i,
       };
       auto element =
           (transform ? transform : RadioboxOption::Simple().transform)(state);