From 49f6efdc3fbfaac66599f99b52eeab1b99ff1153 Mon Sep 17 00:00:00 2001
From: Charles Milette <charles.milette@gmail.com>
Date: Sun, 5 Dec 2021 16:24:23 -0500
Subject: [PATCH 1/2] Fix compilation under Clang

Fixes #1069
---
 cppwinrt/code_writers.h            |  3 ++-
 cppwinrt/cppwinrt.vcxproj          |  3 ++-
 cppwinrt/cppwinrt.vcxproj.filters  |  3 +++
 strings/base_stringable_format.h   | 12 ++++--------
 strings/base_stringable_format_1.h |  9 +++++++++
 5 files changed, 20 insertions(+), 10 deletions(-)
 create mode 100644 strings/base_stringable_format_1.h

diff --git a/cppwinrt/code_writers.h b/cppwinrt/code_writers.h
index c369eb98c..9d4b98e23 100644
--- a/cppwinrt/code_writers.h
+++ b/cppwinrt/code_writers.h
@@ -3259,6 +3259,7 @@ struct __declspec(empty_bases) produce_dispatch_to_overridable<T, D, %>
             w.write(strings::base_reference_produce);
             w.write(strings::base_deferral);
             w.write(strings::base_coroutine_foundation);
+            w.write(strings::base_stringable_format);
         }
         else if (namespace_name == "Windows.Foundation.Collections")
         {
@@ -3295,7 +3296,7 @@ struct __declspec(empty_bases) produce_dispatch_to_overridable<T, D, %>
         if (namespace_name == "Windows.Foundation")
         {
             w.write(strings::base_reference_produce_1);
-            w.write(strings::base_stringable_format);
+            w.write(strings::base_stringable_format_1);
         }
     }
 }
diff --git a/cppwinrt/cppwinrt.vcxproj b/cppwinrt/cppwinrt.vcxproj
index 71272d14f..258feafc6 100644
--- a/cppwinrt/cppwinrt.vcxproj
+++ b/cppwinrt/cppwinrt.vcxproj
@@ -79,9 +79,10 @@
     <ClInclude Include="..\strings\base_security.h" />
     <ClInclude Include="..\strings\base_std_hash.h" />
     <ClInclude Include="..\strings\base_string.h" />
+    <ClInclude Include="..\strings\base_stringable_format.h" />
     <ClInclude Include="..\strings\base_string_input.h" />
     <ClInclude Include="..\strings\base_string_operators.h" />
-    <ClInclude Include="..\strings\base_stringable_format.h" />
+    <ClInclude Include="..\strings\base_stringable_format_1.h" />
     <ClInclude Include="..\strings\base_types.h" />
     <ClInclude Include="..\strings\base_version.h" />
     <ClInclude Include="..\strings\base_version_odr.h" />
diff --git a/cppwinrt/cppwinrt.vcxproj.filters b/cppwinrt/cppwinrt.vcxproj.filters
index bfd56434a..dfe1488ee 100644
--- a/cppwinrt/cppwinrt.vcxproj.filters
+++ b/cppwinrt/cppwinrt.vcxproj.filters
@@ -169,6 +169,9 @@
     <ClInclude Include="..\strings\base_iterator.h">
       <Filter>strings</Filter>
     </ClInclude>
+    <ClInclude Include="..\strings\base_stringable_format_1.h">
+      <Filter>strings</Filter>
+    </ClInclude>
     <ClInclude Include="..\strings\base_stringable_format.h">
       <Filter>strings</Filter>
     </ClInclude>
diff --git a/strings/base_stringable_format.h b/strings/base_stringable_format.h
index 41a54dfd4..f66c21003 100644
--- a/strings/base_stringable_format.h
+++ b/strings/base_stringable_format.h
@@ -1,12 +1,8 @@
 
 #ifdef __cpp_lib_format
-template<>
-struct std::formatter<winrt::Windows::Foundation::IStringable, wchar_t> : std::formatter<winrt::hstring, wchar_t>
+template <typename FormatContext>
+WINRT_IMPL_AUTO(void) std::formatter<winrt::Windows::Foundation::IStringable, wchar_t>::format(winrt::Windows::Foundation::IStringable const& obj, FormatContext& fc)
 {
-    template<typename FormatContext>
-    auto format(winrt::Windows::Foundation::IStringable const& obj, FormatContext& fc)
-    {
-        return std::formatter<winrt::hstring, wchar_t>::format(obj.ToString(), fc);
-    }
-};
+    return std::formatter<winrt::hstring, wchar_t>::format(obj.ToString(), fc);
+}
 #endif
diff --git a/strings/base_stringable_format_1.h b/strings/base_stringable_format_1.h
new file mode 100644
index 000000000..c27f5338c
--- /dev/null
+++ b/strings/base_stringable_format_1.h
@@ -0,0 +1,9 @@
+
+#ifdef __cpp_lib_format
+template <>
+struct std::formatter<winrt::Windows::Foundation::IStringable, wchar_t> : std::formatter<winrt::hstring, wchar_t>
+{
+    template <typename FormatContext>
+    WINRT_IMPL_AUTO(void) format(winrt::Windows::Foundation::IStringable const& obj, FormatContext& fc);
+};
+#endif

From 6592bba90271e51f7f75567894ec26227adfc076 Mon Sep 17 00:00:00 2001
From: Charles Milette <charles.milette@gmail.com>
Date: Sun, 5 Dec 2021 16:27:59 -0500
Subject: [PATCH 2/2] Keep normal auto

---
 strings/base_stringable_format.h   | 2 +-
 strings/base_stringable_format_1.h | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/strings/base_stringable_format.h b/strings/base_stringable_format.h
index f66c21003..86c5acfc6 100644
--- a/strings/base_stringable_format.h
+++ b/strings/base_stringable_format.h
@@ -1,7 +1,7 @@
 
 #ifdef __cpp_lib_format
 template <typename FormatContext>
-WINRT_IMPL_AUTO(void) std::formatter<winrt::Windows::Foundation::IStringable, wchar_t>::format(winrt::Windows::Foundation::IStringable const& obj, FormatContext& fc)
+auto std::formatter<winrt::Windows::Foundation::IStringable, wchar_t>::format(winrt::Windows::Foundation::IStringable const& obj, FormatContext& fc)
 {
     return std::formatter<winrt::hstring, wchar_t>::format(obj.ToString(), fc);
 }
diff --git a/strings/base_stringable_format_1.h b/strings/base_stringable_format_1.h
index c27f5338c..6a7becdfc 100644
--- a/strings/base_stringable_format_1.h
+++ b/strings/base_stringable_format_1.h
@@ -4,6 +4,6 @@ template <>
 struct std::formatter<winrt::Windows::Foundation::IStringable, wchar_t> : std::formatter<winrt::hstring, wchar_t>
 {
     template <typename FormatContext>
-    WINRT_IMPL_AUTO(void) format(winrt::Windows::Foundation::IStringable const& obj, FormatContext& fc);
+    auto format(winrt::Windows::Foundation::IStringable const& obj, FormatContext& fc);
 };
 #endif