wchar.h -> xchar.h because it handles other code unit types too

include/fmt/xchar.h

@@ -0,0 +1,149 @@
+// Formatting library for C++ - optional wchar_t and exotic character support
+//
+// Copyright (c) 2012 - present, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#ifndef FMT_WCHAR_H_
+#define FMT_WCHAR_H_
+
+#include <cwchar>
+
+#include "format.h"
+
+FMT_BEGIN_NAMESPACE
+namespace detail {
+template <typename T>
+using is_exotic_char = bool_constant<!std::is_same<T, char>::value>;
+}
+
+FMT_MODULE_EXPORT_BEGIN
+
+using wstring_view = basic_string_view<wchar_t>;
+using wformat_parse_context = basic_format_parse_context<wchar_t>;
+using wformat_context = buffer_context<wchar_t>;
+using wformat_args = basic_format_args<wformat_context>;
+using wmemory_buffer = basic_memory_buffer<wchar_t>;
+
+#if FMT_GCC_VERSION && FMT_GCC_VERSION < 409
+// Workaround broken conversion on older gcc.
+template <typename... Args> using wformat_string = wstring_view;
+#else
+template <typename... Args>
+using wformat_string = basic_format_string<wchar_t, type_identity_t<Args>...>;
+#endif
+
+template <typename... Args>
+constexpr format_arg_store<wformat_context, Args...> make_wformat_args(
+    const Args&... args) {
+  return {args...};
+}
+
+inline namespace literals {
+constexpr auto operator"" _format(const wchar_t* s, size_t n)
+    -> detail::udl_formatter<wchar_t> {
+  return {{s, n}};
+}
+
+#if FMT_USE_USER_DEFINED_LITERALS && !FMT_USE_NONTYPE_TEMPLATE_PARAMETERS
+constexpr detail::udl_arg<wchar_t> operator"" _a(const wchar_t* s, size_t) {
+  return {s};
+}
+#endif
+}  // namespace literals
+
+template <typename It, typename Sentinel>
+auto join(It begin, Sentinel end, wstring_view sep)
+    -> join_view<It, Sentinel, wchar_t> {
+  return {begin, end, sep};
+}
+
+template <typename Range>
+auto join(Range&& range, wstring_view sep)
+    -> join_view<detail::iterator_t<Range>, detail::sentinel_t<Range>,
+                 wchar_t> {
+  return join(std::begin(range), std::end(range), sep);
+}
+
+template <typename T>
+auto join(std::initializer_list<T> list, wstring_view sep)
+    -> join_view<const T*, const T*, wchar_t> {
+  return join(std::begin(list), std::end(list), sep);
+}
+
+template <typename Locale, typename S, typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_locale<Locale>::value&&
+                            detail::is_exotic_char<Char>::value)>
+inline std::basic_string<Char> vformat(
+    const Locale& loc, const S& format_str,
+    basic_format_args<buffer_context<type_identity_t<Char>>> args) {
+  return detail::vformat(loc, to_string_view(format_str), args);
+}
+
+template <typename Locale, typename S, typename... Args,
+          typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_locale<Locale>::value&&
+                            detail::is_exotic_char<Char>::value)>
+inline std::basic_string<Char> format(const Locale& loc, const S& format_str,
+                                      Args&&... args) {
+  return detail::vformat(loc, to_string_view(format_str),
+                         fmt::make_args_checked<Args...>(format_str, args...));
+}
+
+template <typename Locale, typename S, typename OutputIt, typename... Args,
+          typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value&&
+                            detail::is_locale<Locale>::value&&
+                                detail::is_exotic_char<Char>::value)>
+inline OutputIt vformat_to(
+    OutputIt out, const Locale& loc, const S& format_str,
+    basic_format_args<buffer_context<type_identity_t<Char>>> args) {
+  auto&& buf = detail::get_buffer<Char>(out);
+  vformat_to(buf, to_string_view(format_str), args, detail::locale_ref(loc));
+  return detail::get_iterator(buf);
+}
+
+template <
+    typename OutputIt, typename Locale, typename S, typename... Args,
+    typename Char = char_t<S>,
+    bool enable = detail::is_output_iterator<OutputIt, Char>::value&&
+        detail::is_locale<Locale>::value&& detail::is_exotic_char<Char>::value>
+inline auto format_to(OutputIt out, const Locale& loc, const S& format_str,
+                      Args&&... args) ->
+    typename std::enable_if<enable, OutputIt>::type {
+  const auto& vargs = fmt::make_args_checked<Args...>(format_str, args...);
+  return vformat_to(out, loc, to_string_view(format_str), vargs);
+}
+
+inline void vprint(std::FILE* f, wstring_view fmt, wformat_args args) {
+  wmemory_buffer buffer;
+  detail::vformat_to(buffer, fmt, args);
+  buffer.push_back(L'\0');
+  if (std::fputws(buffer.data(), f) == -1)
+    FMT_THROW(system_error(errno, "cannot write to file"));
+}
+
+inline void vprint(wstring_view fmt, wformat_args args) {
+  vprint(stdout, fmt, args);
+}
+
+template <typename... T>
+void print(std::FILE* f, wformat_string<T...> fmt, T&&... args) {
+  return vprint(f, wstring_view(fmt), make_wformat_args(args...));
+}
+
+template <typename... T> void print(wformat_string<T...> fmt, T&&... args) {
+  return vprint(wstring_view(fmt), make_wformat_args(args...));
+}
+
+/**
+  Converts *value* to ``std::wstring`` using the default format for type *T*.
+ */
+template <typename T> inline std::wstring to_wstring(const T& value) {
+  return format(FMT_STRING(L"{}"), value);
+}
+FMT_MODULE_EXPORT_END
+FMT_END_NAMESPACE
+
+#endif  // FMT_WCHAR_H_