Use EnumFormatter to generate names for EXI devices

This simplifies the code in GameCubePane, and allows us to use the EXIDeviceType enum in error messages.

Source/Core/Common/EnumFormatter.h

@@ -95,7 +95,6 @@ protected:
 
   constexpr explicit EnumFormatter(const array_type names) : m_names(std::move(names)) {}
 
-private:
   const array_type m_names;
   char format_type = 'u';
 };

Source/Core/Core/HW/EXI/EXI_Device.h

@@ -4,7 +4,10 @@
 #pragma once
 
 #include <memory>
+
+#include "Common/Common.h"
 #include "Common/CommonTypes.h"
+#include "Common/EnumFormatter.h"
 
 class PointerWrap;
 
@@ -75,3 +78,50 @@ private:
 std::unique_ptr<IEXIDevice> EXIDevice_Create(EXIDeviceType device_type, int channel_num,
                                              const Memcard::HeaderData& memcard_header_data);
 }  // namespace ExpansionInterface
+
+template <>
+struct fmt::formatter<ExpansionInterface::EXIDeviceType>
+    : EnumFormatter<ExpansionInterface::EXIDeviceType::EthernetTapServer>
+{
+  static constexpr array_type names = {
+      _trans("Dummy"),
+      _trans("Memory Card"),
+      _trans("Mask ROM"),
+      // i18n: A mysterious debugging/diagnostics peripheral for the GameCube.
+      _trans("AD16"),
+      _trans("Microphone"),
+      _trans("Broadband Adapter (TAP)"),
+      _trans("Triforce AM Baseboard"),
+      _trans("USB Gecko"),
+      _trans("GCI Folder"),
+      _trans("Advance Game Port"),
+      _trans("Broadband Adapter (XLink Kai)"),
+      _trans("Broadband Adapter (tapserver)"),
+  };
+
+  constexpr formatter() : EnumFormatter(names) {}
+
+  template <typename FormatContext>
+  auto format(const ExpansionInterface::EXIDeviceType& e, FormatContext& ctx)
+  {
+    if (e != ExpansionInterface::EXIDeviceType::None)
+    {
+      return EnumFormatter::format(e, ctx);
+    }
+    else
+    {
+      // Special-case None since it has a fixed ID (0xff) that is much larger than the rest; we
+      // don't need 200 nullptr entries in names.  We also want to format it specially in the UI.
+      switch (format_type)
+      {
+      default:
+      case 'u':
+        return fmt::format_to(ctx.out(), "None");
+      case 's':
+        return fmt::format_to(ctx.out(), "0xffu /* None */");
+      case 'n':
+        return fmt::format_to(ctx.out(), _trans("<Nothing>"));
+      }
+    }
+  }
+};

Source/Core/DolphinQt/Settings/GameCubePane.cpp

@@ -16,6 +16,7 @@
 #include <QPushButton>
 #include <QVBoxLayout>
 
+#include <array>
 #include <utility>
 
 #include "Common/CommonPaths.h"
@@ -97,31 +98,28 @@ void GameCubePane::CreateWidgets()
   }
 
   // Add slot devices
-  for (const auto& entry : {std::make_pair(tr("<Nothing>"), EXIDeviceType::None),
-                            std::make_pair(tr("Dummy"), EXIDeviceType::Dummy),
-                            std::make_pair(tr("Memory Card"), EXIDeviceType::MemoryCard),
-                            std::make_pair(tr("GCI Folder"), EXIDeviceType::MemoryCardFolder),
-                            std::make_pair(tr("USB Gecko"), EXIDeviceType::Gecko),
-                            std::make_pair(tr("Advance Game Port"), EXIDeviceType::AGP),
-                            std::make_pair(tr("Microphone"), EXIDeviceType::Microphone)})
+  for (const auto device : {EXIDeviceType::None, EXIDeviceType::Dummy, EXIDeviceType::MemoryCard,
+                            EXIDeviceType::MemoryCardFolder, EXIDeviceType::Gecko,
+                            EXIDeviceType::AGP, EXIDeviceType::Microphone})
   {
-    m_slot_combos[0]->addItem(entry.first, static_cast<int>(entry.second));
-    m_slot_combos[1]->addItem(entry.first, static_cast<int>(entry.second));
+    const QString name = tr(fmt::format("{:n}", device).c_str());
+    const int value = static_cast<int>(device);
+    m_slot_combos[0]->addItem(name, value);
+    m_slot_combos[1]->addItem(name, value);
   }
 
   // Add SP1 devices
-  std::vector<std::pair<QString, EXIDeviceType>> sp1Entries{
-      std::make_pair(tr("<Nothing>"), EXIDeviceType::None),
-      std::make_pair(tr("Dummy"), EXIDeviceType::Dummy),
-      std::make_pair(tr("Broadband Adapter (TAP)"), EXIDeviceType::Ethernet),
-      std::make_pair(tr("Broadband Adapter (XLink Kai)"), EXIDeviceType::EthernetXLink)};
-#if defined(__APPLE__)
-  sp1Entries.emplace_back(std::make_pair(tr("Broadband Adapter (tapserver)"),
-                                         ExpansionInterface::EXIDeviceType::EthernetTapServer));
+  for (const auto device : {
+           EXIDeviceType::None,
+           EXIDeviceType::Dummy,
+           EXIDeviceType::Ethernet,
+           EXIDeviceType::EthernetXLink,
+#ifdef __APPLE__
+           EXIDeviceType::EthernetTapServer,
 #endif
-  for (const auto& entry : sp1Entries)
+       })
   {
-    m_slot_combos[2]->addItem(entry.first, static_cast<int>(entry.second));
+    m_slot_combos[2]->addItem(tr(fmt::format("{:n}", device).c_str()), static_cast<int>(device));
   }
 
   device_layout->addWidget(new QLabel(tr("Slot A:")), 0, 0);