More locale

include/fmt/format-inl.h

@@ -116,44 +116,59 @@ template <typename Char> FMT_FUNC Char decimal_point_impl(locale_ref) {
 }
 #endif
 
-FMT_FUNC auto write_int(appender out, basic_format_arg<format_context> value,
+FMT_FUNC auto write_loc(appender out, basic_format_arg<format_context> value,
                         const format_specs& specs, locale_ref loc) -> bool {
 #ifndef FMT_STATIC_THOUSANDS_SEPARATOR
   auto locale = loc.get<std::locale>();
   // We cannot use the num_put<char> facet because it may produce output in
   // a wrong encoding.
-  if (!std::has_facet<format_facet<std::locale>>(locale)) return {};
+  using facet = format_facet<std::locale>;
-  std::use_facet<format_facet<std::locale>>(locale).put(out, value, specs);
+  if (std::has_facet<facet>(locale))
-  return true;
+    return std::use_facet<facet>(locale).put(out, value, specs);
+  return facet(locale).put(out, value, specs);
 #endif
   return false;
 }
 
-struct localize_int {
+struct localizer {
   appender out;
   const format_specs& specs;
   std::string sep;
   std::string grouping;
+  std::string decimal_point;
 
   template <typename T, FMT_ENABLE_IF(detail::is_integer<T>::value)>
-  void operator()(T value) {
+  auto operator()(T value) -> bool {
     auto arg = make_write_int_arg(value, specs.sign);
     write_int(out, static_cast<uint64_or_128_t<T>>(arg.abs_value), arg.prefix,
               specs, digit_grouping<char>(grouping, sep));
+    return true;
   }
-  template <typename T, FMT_ENABLE_IF(!detail::is_integer<T>::value)>
+
-  void operator()(T) {}
+  template <typename T, FMT_ENABLE_IF(detail::is_floating_point<T>::value)>
+  auto operator()(T) -> bool {
+    return false;
+  }
+
+  auto operator()(...) -> bool { return false; }
 };
 }  // namespace detail
 
 template <typename Locale> typename Locale::id format_facet<Locale>::id;
 
 #ifndef FMT_STATIC_THOUSANDS_SEPARATOR
+template <typename Locale> format_facet<Locale>::format_facet(Locale& loc) {
+  auto& numpunct = std::use_facet<std::numpunct<char>>(loc);
+  grouping_ = numpunct.grouping();
+  if (!grouping_.empty()) separator_ = std::string(1, numpunct.thousands_sep());
+}
+
 template <>
-FMT_API FMT_FUNC void format_facet<std::locale>::do_put(
+FMT_API FMT_FUNC auto format_facet<std::locale>::do_put(
     appender out, basic_format_arg<format_context> val,
-    const format_specs& specs) const {
+    const format_specs& specs) const -> bool {
-  visit_format_arg(detail::localize_int{out, specs, separator_, grouping_},
+  return visit_format_arg(
+      detail::localizer{out, specs, separator_, grouping_, decimal_point_},
       val);
 }
 #endif

include/fmt/format.h

@@ -992,21 +992,26 @@ template <typename Locale> class format_facet : public Locale::facet {
  private:
   std::string separator_;
   std::string grouping_;
+  std::string decimal_point_;
 
  protected:
-  virtual void do_put(appender out, basic_format_arg<format_context> val,
+  virtual auto do_put(appender out, basic_format_arg<format_context> val,
-                      const format_specs& specs) const;
+                      const format_specs& specs) const -> bool;
 
  public:
   static FMT_API typename Locale::id id;
 
-  explicit format_facet(string_view sep = ",",
+  explicit format_facet(Locale& loc);
-                        std::initializer_list<unsigned char> g = {3})
+  explicit format_facet(string_view sep = "",
-      : separator_(sep.data(), sep.size()), grouping_(g.begin(), g.end()) {}
+                        std::initializer_list<unsigned char> g = {3},
+                        std::string decimal_point = ".")
+      : separator_(sep.data(), sep.size()),
+        grouping_(g.begin(), g.end()),
+        decimal_point_(decimal_point) {}
 
-  void put(appender out, basic_format_arg<format_context> val,
+  auto put(appender out, basic_format_arg<format_context> val,
-           const format_specs& specs) const {
+           const format_specs& specs) const -> bool {
-    do_put(out, val, specs);
+    return do_put(out, val, specs);
   }
 };
 
@@ -2042,10 +2047,11 @@ auto write_int(OutputIt out, UInt value, unsigned prefix,
       });
 }
 
-FMT_API auto write_int(appender out, basic_format_arg<format_context> value,
+// Writes value with localization.
+FMT_API auto write_loc(appender out, basic_format_arg<format_context> value,
                        const format_specs& specs, locale_ref loc) -> bool;
 template <typename OutputIt, typename Char>
-inline auto write_int(OutputIt, basic_format_arg<buffer_context<Char>>,
+inline auto write_loc(OutputIt, basic_format_arg<buffer_context<Char>>,
                       const basic_format_specs<Char>&, locale_ref) -> bool {
   return false;
 }
@@ -4165,8 +4171,8 @@ void vformat_to(buffer<Char>& buf, basic_string_view<Char> fmt,
       begin = parse_format_specs(begin, end, handler);
       if (begin == end || *begin != '}')
         on_error("missing '}' in format string");
-      if (specs.localized && arg.is_integral() &&
+      if (specs.localized &&
-          write_int(context.out(), arg, specs, context.locale())) {
+          write_loc(context.out(), arg, specs, context.locale())) {
         return begin;
       }
       auto f = arg_formatter<Char>{context.out(), specs, context.locale()};

test/format-test.cc

@@ -2322,21 +2322,25 @@ class format_facet : public fmt::format_facet<std::locale> {
     fmt::appender out;
 
     template <typename T, FMT_ENABLE_IF(fmt::detail::is_integer<T>::value)>
-    void operator()(T value) {
+    auto operator()(T value) -> bool {
       fmt::format_to(out, "[{}]", value);
+      return true;
     }
+
     template <typename T, FMT_ENABLE_IF(!fmt::detail::is_integer<T>::value)>
-    void operator()(T) {}
+    auto operator()(T) -> bool {
+      return false;
+    }
   };
 
-  void do_put(fmt::appender out, fmt::basic_format_arg<fmt::format_context> arg,
+  auto do_put(fmt::appender out, fmt::basic_format_arg<fmt::format_context> arg,
-              const fmt::format_specs&) const override;
+              const fmt::format_specs&) const -> bool override;
 };
 
-void format_facet::do_put(fmt::appender out,
+auto format_facet::do_put(fmt::appender out,
                           fmt::basic_format_arg<fmt::format_context> arg,
-                          const fmt::format_specs&) const {
+                          const fmt::format_specs&) const -> bool {
-  visit_format_arg(int_formatter{out}, arg);
+  return visit_format_arg(int_formatter{out}, arg);
 }
 
 TEST(format_test, format_facet) {