From a7a108a0905d532c9a5fae7af53d340d1f97c151 Mon Sep 17 00:00:00 2001
From: David Machaj <46852402+dmachaj@users.noreply.github.com.>
Date: Mon, 11 Nov 2024 14:45:01 -0800
Subject: [PATCH] Reduce the code size of generated consume methods by skipping
 casts when the type is already a match

---
 cppwinrt/code_writers.h | 52 +++++++++++++++++++++++++++++++----------
 strings/base_error.h    |  3 +--
 2 files changed, 41 insertions(+), 14 deletions(-)

diff --git a/cppwinrt/code_writers.h b/cppwinrt/code_writers.h
index 0e516b528..f93279a74 100644
--- a/cppwinrt/code_writers.h
+++ b/cppwinrt/code_writers.h
@@ -1135,10 +1135,18 @@ namespace cppwinrt
                 // immediately while preserving the error code and local variables.
                 format = R"(    template <typename D%> auto consume_%<D%>::%(%) const noexcept
     {%
-        auto const& castedResult = static_cast<% const&>(static_cast<D const&>(*this));
-        auto const abiType = *(abi_t<%>**)&castedResult;
-        check_cast_result(abiType);
-        abiType->%(%);%
+        if constexpr (!std::is_same_v<D, %>)
+        {
+            auto const& castedResult = static_cast<% const&>(static_cast<D const&>(*this));
+            auto const abiType = *(abi_t<%>**)&castedResult;
+            check_cast_result(abiType);
+            abiType->%(%);
+        }
+        else
+        {
+            auto const abiType = *(abi_t<%>**)this;
+            abiType->%(%);
+        }%
     }
 )";
             }
@@ -1146,10 +1154,18 @@ namespace cppwinrt
             {
                 format = R"(    template <typename D%> auto consume_%<D%>::%(%) const noexcept
     {%
-        auto const& castedResult = static_cast<% const&>(static_cast<D const&>(*this));
-        auto const abiType = *(abi_t<%>**)&castedResult;
-        check_cast_result(abiType);
-        WINRT_VERIFY_(0, abiType->%(%));%
+        if constexpr (!std::is_same_v<D, %>)
+        {
+            auto const& castedResult = static_cast<% const&>(static_cast<D const&>(*this));
+            auto const abiType = *(abi_t<%>**)&castedResult;
+            check_cast_result(abiType);
+            WINRT_VERIFY_(0, abiType->%(%));
+        }
+        else
+        {
+            auto const abiType = *(abi_t<%>**)this;
+            WINRT_VERIFY_(0, abiType->%(%));
+        }%
     }
 )";
             }
@@ -1158,10 +1174,18 @@ namespace cppwinrt
         {
             format = R"(    template <typename D%> auto consume_%<D%>::%(%) const
     {%
-        auto const& castedResult = static_cast<% const&>(static_cast<D const&>(*this));
-        auto const abiType = *(abi_t<%>**)&castedResult;
-        check_cast_result(abiType);
-        check_hresult(abiType->%(%));%
+        if constexpr (!std::is_same_v<D, %>)
+        {
+            auto const& castedResult = static_cast<% const&>(static_cast<D const&>(*this));
+            auto const abiType = *(abi_t<%>**)&castedResult;
+            check_cast_result(abiType);
+            check_hresult(abiType->%(%));
+        }
+        else
+        {
+            auto const abiType = *(abi_t<%>**)this;
+            check_hresult(abiType->%(%));
+        }%
     }
 )";
         }
@@ -1175,6 +1199,10 @@ namespace cppwinrt
             bind<write_consume_return_type>(signature, false),
             type,
             type,
+            type,
+            get_abi_name(method),
+            bind<write_abi_args>(signature),
+            type,
             get_abi_name(method),
             bind<write_abi_args>(signature),
             bind<write_consume_return_statement>(signature));
diff --git a/strings/base_error.h b/strings/base_error.h
index 21010ccb2..9b9624277 100644
--- a/strings/base_error.h
+++ b/strings/base_error.h
@@ -539,8 +539,7 @@ namespace winrt::impl
         return result;
     }
 
-    template <typename T>
-    WINRT_IMPL_NOINLINE void check_cast_result(T* from, winrt::impl::slim_source_location const& sourceInformation = winrt::impl::slim_source_location::current())
+    inline WINRT_IMPL_NOINLINE void check_cast_result(void* from, winrt::impl::slim_source_location const& sourceInformation = winrt::impl::slim_source_location::current())
     {
         if (!from)
         {