Remove formatUnchecked and extend i18n api with format check. (#1274)

While we can not check translated string, it is still make sense
to check the original string at compile time.

It also simplify the usage and solve the issue that runtime_format_string
is not available at c++20.

src/im/keyboard/keyboard.cpp

@@ -253,8 +253,7 @@ std::vector<InputMethodEntry> KeyboardEngine::listInputMethods() {
         auto language = findBestLanguage(isoCodes, layoutInfo.description,
                                          layoutInfo.languages);
         auto description =
-            formatUnchecked(_("Keyboard - {0}"),
-                            D_("xkeyboard-config", layoutInfo.description));
+            _("Keyboard - {0}", D_("xkeyboard-config", layoutInfo.description));
         auto uniqueName = imNamePrefix + layoutInfo.name;
         if (uniqueName == "keyboard-us") {
             usExists = true;
@@ -271,10 +270,10 @@ std::vector<InputMethodEntry> KeyboardEngine::listInputMethods() {
                                              !variantInfo.languages.empty()
                                                  ? variantInfo.languages
                                                  : layoutInfo.languages);
-            auto description = formatUnchecked(
-                _("Keyboard - {0} - {1}"),
-                D_("xkeyboard-config", layoutInfo.description),
-                D_("xkeyboard-config", variantInfo.description));
+            auto description =
+                _("Keyboard - {0} - {1}",
+                  D_("xkeyboard-config", layoutInfo.description),
+                  D_("xkeyboard-config", variantInfo.description));
             auto uniqueName = stringutils::concat(imNamePrefix, layoutInfo.name,
                                                   "-", variantInfo.name);
 
@@ -311,13 +310,12 @@ std::vector<InputMethodEntry> KeyboardEngine::listInputMethods() {
                 if (uniqueName == "keyboard-us") {
                     usExists = true;
                 }
-                result.push_back(std::move(
-                    InputMethodEntry(
-                        uniqueName,
-                        formatUnchecked(_("{0} (Not Available)"), *desc), *lang,
-                        "keyboard")
-                        .setLabel(*label)
-                        .setIcon("input-keyboard")));
+                result.push_back(
+                    std::move(InputMethodEntry(uniqueName,
+                                               _("{0} (Not Available)", *desc),
+                                               *lang, "keyboard")
+                                  .setLabel(*label)
+                                  .setIcon("input-keyboard")));
             }
         }
     } else {

src/lib/fcitx-utils/i18n.h

@@ -8,7 +8,11 @@
 #define _FCITX_UTILS_I18N_H_
 
 #include <string>
+#include <utility>
 #include <fcitx-utils/fcitxutils_export.h>
+#if __cplusplus >= 202002L
+#include <format>
+#endif
 
 namespace fcitx {
 
@@ -28,19 +32,54 @@ translateDomainCtx(const char *domain, const char *ctx, const std::string &s);
 FCITXUTILS_EXPORT const char *
 translateDomainCtx(const char *domain, const char *ctx, const char *s);
 FCITXUTILS_EXPORT void registerDomain(const char *domain, const char *dir);
+
+#if __cplusplus >= 202002L
+template <typename... Args>
+auto translate(std::format_string<Args...> s, Args &&...args)
+    -> std::enable_if_t<(sizeof...(Args) >= 1), std::string> {
+    return std::vformat(translate(std::string(s.get())),
+                        std::make_format_args(args...));
+}
+
+template <typename... Args>
+auto translateCtx(const char *ctx, std::format_string<Args...> s,
+                  Args &&...args)
+    -> std::enable_if_t<(sizeof...(Args) >= 1), std::string> {
+    return std::vformat(translateCtx(ctx, std::string(s.get())),
+                        std::make_format_args(args...));
+}
+
+template <typename... Args>
+auto translateDomain(const char *domain, std::format_string<Args...> s,
+                     Args &&...args)
+    -> std::enable_if_t<(sizeof...(Args) >= 1), std::string> {
+    return std::vformat(translateDomain(domain, std::string(s.get())),
+                        std::make_format_args(args...));
+}
+
+template <typename... Args>
+auto translateDomainCtx(const char *domain, const char *ctx,
+                        std::format_string<Args...> s, Args &&...args)
+    -> std::enable_if_t<(sizeof...(Args) >= 1), std::string> {
+    return std::vformat(translateDomainCtx(domain, ctx, std::string(s.get())),
+                        std::make_format_args(args...));
+}
+#endif
+
 } // namespace fcitx
 
 #ifndef FCITX_NO_I18N_MACRO
 
 #ifdef FCITX_GETTEXT_DOMAIN
-#define _(x) ::fcitx::translateDomain(FCITX_GETTEXT_DOMAIN, x)
-#define C_(c, x) ::fcitx::translateDomainCtx(FCITX_GETTEXT_DOMAIN, c, x)
+#define _(...) ::fcitx::translateDomain(FCITX_GETTEXT_DOMAIN, __VA_ARGS__)
+#define C_(c, ...)                                                             \
+    ::fcitx::translateDomainCtx(FCITX_GETTEXT_DOMAIN, c, __VA_ARGS__)
 #else
-#define _(x) ::fcitx::translate(x)
-#define C_(c, x) ::fcitx::translateCtx(c, x)
+#define _(...) ::fcitx::translate(__VA_ARGS__)
+#define C_(c, ...) ::fcitx::translateCtx(c, __VA_ARGS__)
 #endif
 
-#define D_(d, x) ::fcitx::translateDomain(d, x)
+#define D_(d, ...) ::fcitx::translateDomain(d, __VA_ARGS__)
 
 #define NC_(c, x) (x)
 #define N_(x) (x)

src/lib/fcitx-utils/misc_p.h

@@ -23,7 +23,6 @@
 #include <fcitx-utils/endian_p.h>
 #include <fcitx-utils/environ.h>
 #include <fcitx-utils/macros.h>
-#include <format>
 #include "config.h" // IWYU pragma: keep
 
 #ifdef _WIN32
@@ -339,12 +338,6 @@ static inline uint32_t FromLittleEndian32(const T *d) {
     return le32toh(t);
 }
 
-template <typename... Args>
-FCITX_NODISCARD inline std::string formatUnchecked(std::string_view fmt,
-                                                   Args &&...args) {
-    return std::vformat(fmt, std::make_format_args(args...));
-}
-
 } // namespace fcitx
 
 #endif // _FCITX_UTILS_MISC_P_H_

src/lib/fcitx/instance.cpp

@@ -374,8 +374,7 @@ void InstancePrivate::buildDefaultGroup() {
         if (imLayouts.size() == 1) {
             groupName = _("Default");
         } else {
-            groupName =
-                formatUnchecked(_("Group {}"), imManager_.groupCount() + 1);
+            groupName = _("Group {}", imManager_.groupCount() + 1);
         }
         imManager_.addEmptyGroup(groupName);
         groupOrders.push_back(groupName);
@@ -421,17 +420,16 @@ void InstancePrivate::showInputMethodInformation(InputContext *ic) {
         } else if (subMode.empty()) {
             display = std::move(name);
         } else {
-            display = formatUnchecked(_("{0} ({1})"), name, subMode);
+            display = _("{0} ({1})", name, subMode);
         }
     } else if (entry) {
-        display = formatUnchecked(_("{0} (Not available)"), entry->name());
+        display = _("{0} (Not available)", entry->name());
     } else {
         display = _("(Not available)");
     }
     if (!globalConfig_.compactInputMethodInformation() &&
         imManager.groupCount() > 1) {
-        display = formatUnchecked(_("Group {0}: {1}"),
-                                  imManager.currentGroup().name(), display);
+        display = _("Group {0}: {1}", imManager.currentGroup().name(), display);
     }
     inputState->showInputMethodInformation(display);
 }
@@ -467,9 +465,8 @@ void InstancePrivate::navigateGroup(InputContext *ic, const Key &key,
         notifications_->call<INotifications::showTip>(
             "enumerate-group", _("Input Method"), "input-keyboard",
             _("Switch group"),
-            formatUnchecked(
-                _("Switch group to {0}"),
-                imManager_.groups()[inputState->pendingGroupIndex_]),
+            _("Switch group to {0}",
+              imManager_.groups()[inputState->pendingGroupIndex_]),
             3000);
     }
 }
@@ -697,8 +694,8 @@ Instance::Instance(int argc, char **argv) {
                     d->notifications_->call<INotifications::showTip>(
                         "enumerate-group", _("Input Method"), "input-keyboard",
                         _("Switch group"),
-                        formatUnchecked(_("Switched group to {0}"),
-                                        d->imManager_.currentGroup().name()),
+                        _("Switched group to {0}",
+                          d->imManager_.currentGroup().name()),
                         3000);
                 }
                 d->lastGroup_ = newGroup;

src/modules/xcb/xcbconnection.cpp

@@ -563,9 +563,7 @@ void XCBConnection::navigateGroup(const Key &key, bool forward) {
         parent_->notifications()->call<INotifications::showTip>(
             "enumerate-group", _("Input Method"), "input-keyboard",
             _("Switch group"),
-            formatUnchecked(_("Switch group to {0}"),
-                            imManager.groups()[groupIndex_]),
-            3000);
+            _("Switch group to {0}", imManager.groups()[groupIndex_]), 3000);
     }
 }