win32/HResult: un-inline HRESULTToString() to reduce header dependencies

src/win32/HResult.cxx

@@ -25,6 +25,45 @@
 #include <cstdio>
 #include <memory>
 
+#include <audiopolicy.h>
+
+std::string_view
+HRESULTToString(HRESULT result) noexcept
+{
+	using namespace std::literals;
+	switch (result) {
+#define C(x)                                                                             \
+case x:                                                                                  \
+	return #x##sv
+		C(AUDCLNT_E_ALREADY_INITIALIZED);
+		C(AUDCLNT_E_BUFDURATION_PERIOD_NOT_EQUAL);
+		C(AUDCLNT_E_BUFFER_ERROR);
+		C(AUDCLNT_E_BUFFER_OPERATION_PENDING);
+		C(AUDCLNT_E_BUFFER_SIZE_ERROR);
+		C(AUDCLNT_E_BUFFER_SIZE_NOT_ALIGNED);
+		C(AUDCLNT_E_BUFFER_TOO_LARGE);
+		C(AUDCLNT_E_CPUUSAGE_EXCEEDED);
+		C(AUDCLNT_E_DEVICE_INVALIDATED);
+		C(AUDCLNT_E_DEVICE_IN_USE);
+		C(AUDCLNT_E_ENDPOINT_CREATE_FAILED);
+		C(AUDCLNT_E_EXCLUSIVE_MODE_NOT_ALLOWED);
+		C(AUDCLNT_E_INVALID_DEVICE_PERIOD);
+		C(AUDCLNT_E_OUT_OF_ORDER);
+		C(AUDCLNT_E_SERVICE_NOT_RUNNING);
+		C(AUDCLNT_E_UNSUPPORTED_FORMAT);
+		C(AUDCLNT_E_WRONG_ENDPOINT_TYPE);
+		C(AUDCLNT_E_NOT_INITIALIZED);
+		C(AUDCLNT_E_NOT_STOPPED);
+		C(CO_E_NOTINITIALIZED);
+		C(E_INVALIDARG);
+		C(E_OUTOFMEMORY);
+		C(E_POINTER);
+		C(NO_ERROR);
+#undef C
+	}
+	return std::string_view();
+}
+
 std::string
 HResultCategory::message(int Errcode) const
 {

src/win32/HResult.hxx

@@ -25,42 +25,11 @@
 #include <string_view>
 #include <system_error>
 
-#include <audiopolicy.h>
+#include <windef.h>
 
-constexpr std::string_view HRESULTToString(HRESULT result) {
-	using namespace std::literals;
-	switch (result) {
-#define C(x)                                                                             \
-case x:                                                                                  \
-	return #x##sv
-		C(AUDCLNT_E_ALREADY_INITIALIZED);
-		C(AUDCLNT_E_BUFDURATION_PERIOD_NOT_EQUAL);
-		C(AUDCLNT_E_BUFFER_ERROR);
-		C(AUDCLNT_E_BUFFER_OPERATION_PENDING);
-		C(AUDCLNT_E_BUFFER_SIZE_ERROR);
-		C(AUDCLNT_E_BUFFER_SIZE_NOT_ALIGNED);
-		C(AUDCLNT_E_BUFFER_TOO_LARGE);
-		C(AUDCLNT_E_CPUUSAGE_EXCEEDED);
-		C(AUDCLNT_E_DEVICE_INVALIDATED);
-		C(AUDCLNT_E_DEVICE_IN_USE);
-		C(AUDCLNT_E_ENDPOINT_CREATE_FAILED);
-		C(AUDCLNT_E_EXCLUSIVE_MODE_NOT_ALLOWED);
-		C(AUDCLNT_E_INVALID_DEVICE_PERIOD);
-		C(AUDCLNT_E_OUT_OF_ORDER);
-		C(AUDCLNT_E_SERVICE_NOT_RUNNING);
-		C(AUDCLNT_E_UNSUPPORTED_FORMAT);
-		C(AUDCLNT_E_WRONG_ENDPOINT_TYPE);
-		C(AUDCLNT_E_NOT_INITIALIZED);
-		C(AUDCLNT_E_NOT_STOPPED);
-		C(CO_E_NOTINITIALIZED);
-		C(E_INVALIDARG);
-		C(E_OUTOFMEMORY);
-		C(E_POINTER);
-		C(NO_ERROR);
-#undef C
-	}
-	return std::string_view();
-}
+gcc_const
+std::string_view
+HRESULTToString(HRESULT result) noexcept;
 
 static inline const std::error_category &hresult_category() noexcept;
 class HResultCategory : public std::error_category {