Upgrade to fmt 9.0.0

This library tends to break in annoying ways like this, so pin the major
version to 9 to hopefully avoid these problems in the future.

1 files changed, 130 insertions, 94 deletions

diff --git a/subprojects/fmt/include/fmt/ostream.h b/subprojects/fmt/include/fmt/ostream.h
index 29c58ec..394d947 100644
--- a/subprojects/fmt/include/fmt/ostream.h
+++ b/subprojects/fmt/include/fmt/ostream.h
@@ -8,89 +8,97 @@
 #ifndef FMT_OSTREAM_H_
 #define FMT_OSTREAM_H_
 
+#include <fstream>
 #include <ostream>
 
 #include "format.h"
 
 FMT_BEGIN_NAMESPACE
 
-template <typename Char> class basic_printf_parse_context;
 template <typename OutputIt, typename Char> class basic_printf_context;
 
 namespace detail {
 
-template <class Char> class formatbuf : public std::basic_streambuf<Char> {
+// Checks if T has a user-defined operator<<.
+template <typename T, typename Char, typename Enable = void>
+class is_streamable {
  private:
-  using int_type = typename std::basic_streambuf<Char>::int_type;
-  using traits_type = typename std::basic_streambuf<Char>::traits_type;
+  template <typename U>
+  static auto test(int)
+      -> bool_constant<sizeof(std::declval<std::basic_ostream<Char>&>()
+                              << std::declval<U>()) != 0>;
+
+  template <typename> static auto test(...) -> std::false_type;
 
-  buffer<Char>& buffer_;
+  using result = decltype(test<T>(0));
 
  public:
-  formatbuf(buffer<Char>& buf) : buffer_(buf) {}
-
- protected:
-  // The put-area is actually always empty. This makes the implementation
-  // simpler and has the advantage that the streambuf and the buffer are always
-  // in sync and sputc never writes into uninitialized memory. The obvious
-  // disadvantage is that each call to sputc always results in a (virtual) call
-  // to overflow. There is no disadvantage here for sputn since this always
-  // results in a call to xsputn.
-
-  int_type overflow(int_type ch = traits_type::eof()) FMT_OVERRIDE {
-    if (!traits_type::eq_int_type(ch, traits_type::eof()))
-      buffer_.push_back(static_cast<Char>(ch));
-    return ch;
-  }
+  is_streamable() = default;
 
-  std::streamsize xsputn(const Char* s, std::streamsize count) FMT_OVERRIDE {
-    buffer_.append(s, s + count);
-    return count;
-  }
+  static const bool value = result::value;
 };
 
-struct converter {
-  template <typename T, FMT_ENABLE_IF(is_integral<T>::value)> converter(T);
-};
+// Formatting of built-in types and arrays is intentionally disabled because
+// it's handled by standard (non-ostream) formatters.
+template <typename T, typename Char>
+struct is_streamable<
+    T, Char,
+    enable_if_t<
+        std::is_arithmetic<T>::value || std::is_array<T>::value ||
+        std::is_pointer<T>::value || std::is_same<T, char8_type>::value ||
+        std::is_convertible<T, fmt::basic_string_view<Char>>::value ||
+        std::is_same<T, std_string_view<Char>>::value ||
+        (std::is_convertible<T, int>::value && !std::is_enum<T>::value)>>
+    : std::false_type {};
+
+template <typename Char> FILE* get_file(std::basic_filebuf<Char>&) {
+  return nullptr;
+}
 
-template <typename Char> struct test_stream : std::basic_ostream<Char> {
- private:
-  void_t<> operator<<(converter);
+struct dummy_filebuf {
+  FILE* _Myfile;
 };
-
-// Hide insertion operators for built-in types.
-template <typename Char, typename Traits>
-void_t<> operator<<(std::basic_ostream<Char, Traits>&, Char);
-template <typename Char, typename Traits>
-void_t<> operator<<(std::basic_ostream<Char, Traits>&, char);
-template <typename Traits>
-void_t<> operator<<(std::basic_ostream<char, Traits>&, char);
-template <typename Traits>
-void_t<> operator<<(std::basic_ostream<char, Traits>&, signed char);
-template <typename Traits>
-void_t<> operator<<(std::basic_ostream<char, Traits>&, unsigned char);
-
-// Checks if T has a user-defined operator<< (e.g. not a member of
-// std::ostream).
-template <typename T, typename Char> class is_streamable {
- private:
-  template <typename U>
-  static bool_constant<!std::is_same<decltype(std::declval<test_stream<Char>&>()
-                                              << std::declval<U>()),
-                                     void_t<>>::value>
-  test(int);
-
-  template <typename> static std::false_type test(...);
-
-  using result = decltype(test<T>(0));
-
- public:
-  static const bool value = result::value;
+template <typename T, typename U = int> struct ms_filebuf {
+  using type = dummy_filebuf;
 };
+template <typename T> struct ms_filebuf<T, decltype(T::_Myfile, 0)> {
+  using type = T;
+};
+using filebuf_type = ms_filebuf<std::filebuf>::type;
+
+FILE* get_file(filebuf_type& buf);
+
+// Generate a unique explicit instantion in every translation unit using a tag
+// type in an anonymous namespace.
+namespace {
+struct filebuf_access_tag {};
+}  // namespace
+template <typename Tag, typename FileMemberPtr, FileMemberPtr file>
+class filebuf_access {
+  friend FILE* get_file(filebuf_type& buf) { return buf.*file; }
+};
+template class filebuf_access<filebuf_access_tag,
+                              decltype(&filebuf_type::_Myfile),
+                              &filebuf_type::_Myfile>;
+
+inline bool write(std::filebuf& buf, fmt::string_view data) {
+  FILE* f = get_file(buf);
+  if (!f) return false;
+  print(f, data);
+  return true;
+}
+inline bool write(std::wfilebuf&, fmt::basic_string_view<wchar_t>) {
+  return false;
+}
 
 // Write the content of buf to os.
+// It is a separate function rather than a part of vprint to simplify testing.
 template <typename Char>
 void write_buffer(std::basic_ostream<Char>& os, buffer<Char>& buf) {
+  if (const_check(FMT_MSC_VERSION)) {
+    auto filebuf = dynamic_cast<std::basic_filebuf<Char>*>(os.rdbuf());
+    if (filebuf && write(*filebuf, {buf.data(), buf.size()})) return;
+  }
   const Char* buf_data = buf.data();
   using unsigned_streamsize = std::make_unsigned<std::streamsize>::type;
   unsigned_streamsize size = buf.size();
@@ -106,53 +114,74 @@ void write_buffer(std::basic_ostream<Char>& os, buffer<Char>& buf) {
 template <typename Char, typename T>
 void format_value(buffer<Char>& buf, const T& value,
                   locale_ref loc = locale_ref()) {
-  formatbuf<Char> format_buf(buf);
-  std::basic_ostream<Char> output(&format_buf);
+  auto&& format_buf = formatbuf<std::basic_streambuf<Char>>(buf);
+  auto&& output = std::basic_ostream<Char>(&format_buf);
 #if !defined(FMT_STATIC_THOUSANDS_SEPARATOR)
   if (loc) output.imbue(loc.get<std::locale>());
 #endif
   output << value;
   output.exceptions(std::ios_base::failbit | std::ios_base::badbit);
-  buf.try_resize(buf.size());
 }
 
-// Formats an object of type T that has an overloaded ostream operator<<.
-template <typename T, typename Char>
-struct fallback_formatter<T, Char, enable_if_t<is_streamable<T, Char>::value>>
-    : private formatter<basic_string_view<Char>, Char> {
-  FMT_CONSTEXPR auto parse(basic_format_parse_context<Char>& ctx)
-      -> decltype(ctx.begin()) {
-    return formatter<basic_string_view<Char>, Char>::parse(ctx);
-  }
-  template <typename ParseCtx,
-            FMT_ENABLE_IF(std::is_same<
-                          ParseCtx, basic_printf_parse_context<Char>>::value)>
-  auto parse(ParseCtx& ctx) -> decltype(ctx.begin()) {
-    return ctx.begin();
-  }
+template <typename T> struct streamed_view { const T& value; };
 
-  template <typename OutputIt>
-  auto format(const T& value, basic_format_context<OutputIt, Char>& ctx)
+}  // namespace detail
+
+// Formats an object of type T that has an overloaded ostream operator<<.
+template <typename Char>
+struct basic_ostream_formatter : formatter<basic_string_view<Char>, Char> {
+  template <typename T, typename OutputIt>
+  auto format(const T& value, basic_format_context<OutputIt, Char>& ctx) const
       -> OutputIt {
-    basic_memory_buffer<Char> buffer;
+    auto buffer = basic_memory_buffer<Char>();
     format_value(buffer, value, ctx.locale());
-    basic_string_view<Char> str(buffer.data(), buffer.size());
-    return formatter<basic_string_view<Char>, Char>::format(str, ctx);
+    return formatter<basic_string_view<Char>, Char>::format(
+        {buffer.data(), buffer.size()}, ctx);
   }
+};
+
+using ostream_formatter = basic_ostream_formatter<char>;
+
+template <typename T>
+struct formatter<detail::streamed_view<T>> : ostream_formatter {
   template <typename OutputIt>
-  auto format(const T& value, basic_printf_context<OutputIt, Char>& ctx)
-      -> OutputIt {
-    basic_memory_buffer<Char> buffer;
-    format_value(buffer, value, ctx.locale());
-    return std::copy(buffer.begin(), buffer.end(), ctx.out());
+  auto format(detail::streamed_view<T> view,
+              basic_format_context<OutputIt, char>& ctx) const -> OutputIt {
+    return ostream_formatter::format(view.value, ctx);
   }
 };
+
+/**
+  \rst
+  Returns a view that formats `value` via an ostream ``operator<<``.
+
+  **Example**::
+
+    fmt::print("Current thread id: {}\n",
+               fmt::streamed(std::this_thread::get_id()));
+  \endrst
+ */
+template <typename T>
+auto streamed(const T& value) -> detail::streamed_view<T> {
+  return {value};
+}
+
+namespace detail {
+
+// Formats an object of type T that has an overloaded ostream operator<<.
+template <typename T, typename Char>
+struct fallback_formatter<T, Char, enable_if_t<is_streamable<T, Char>::value>>
+    : basic_ostream_formatter<Char> {
+  using basic_ostream_formatter<Char>::format;
+};
+
 }  // namespace detail
 
-template <typename Char>
-void vprint(std::basic_ostream<Char>& os, basic_string_view<Char> format_str,
+FMT_MODULE_EXPORT template <typename Char>
+void vprint(std::basic_ostream<Char>& os,
+            basic_string_view<type_identity_t<Char>> format_str,
             basic_format_args<buffer_context<type_identity_t<Char>>> args) {
-  basic_memory_buffer<Char> buffer;
+  auto buffer = basic_memory_buffer<Char>();
   detail::vformat_to(buffer, format_str, args);
   detail::write_buffer(os, buffer);
 }
@@ -166,12 +195,19 @@ void vprint(std::basic_ostream<Char>& os, basic_string_view<Char> format_str,
     fmt::print(cerr, "Don't {}!", "panic");
   \endrst
  */
-template <typename S, typename... Args,
-          typename Char = enable_if_t<detail::is_string<S>::value, char_t<S>>>
-void print(std::basic_ostream<Char>& os, const S& format_str, Args&&... args) {
-  vprint(os, to_string_view(format_str),
-         fmt::make_args_checked<Args...>(format_str, args...));
+FMT_MODULE_EXPORT template <typename... T>
+void print(std::ostream& os, format_string<T...> fmt, T&&... args) {
+  vprint(os, fmt, fmt::make_format_args(args...));
 }
+
+FMT_MODULE_EXPORT
+template <typename... Args>
+void print(std::wostream& os,
+           basic_format_string<wchar_t, type_identity_t<Args>...> fmt,
+           Args&&... args) {
+  vprint(os, fmt, fmt::make_format_args<buffer_context<wchar_t>>(args...));
+}
+
 FMT_END_NAMESPACE
 
 #endif  // FMT_OSTREAM_H_