Unhack the string_view workaround in llpreviewgesture, with a slightly less hacky hack in llstring. lol. Thanks Liru for making this as lean as ancient gcc can stand it to be.

indra/cmake/00-Common.cmake

@@ -85,6 +85,7 @@ if (WINDOWS)
       /TP
       /W3
       /c
+      /Zc:__cplusplus
       /Zc:forScope
       /Zc:rvalueCast
       /Zc:wchar_t

indra/llcommon/CMakeLists.txt

@@ -300,6 +300,7 @@ target_link_libraries(
     ${CORESERVICES_LIBRARY}
     ${URIPARSER_LIBRARY}
     nlohmann_json::nlohmann_json
+    absl::strings
     ${RT_LIBRARY}
     )
 

indra/llcommon/llstring.h

@@ -29,6 +29,16 @@
 
 #include <boost/optional/optional.hpp>
 #include <string>
+
+#if __cplusplus < 201606
+#include <absl/strings/string_view.h>
+namespace std {
+    typedef absl::string_view string_view;
+}
+#else
+    #include <string_view>
+#endif
+
 #include <cstdio>
 //#include <locale>
 #include <iomanip>

indra/newview/llpreviewgesture.cpp

@@ -1609,22 +1609,8 @@ std::string LLPreviewGesture::getLabel(const std::vector<std::string>& v_labels)
 			for(const auto& pair : LLPreview::sInstances)
 			{
 				const auto& pPreview(pair.second);
-#ifndef LL_WINDOWS
-#if __cplusplus >= 201606
 				constexpr std::string_view gesture("Gesture");
-				if (pPreview && pPreview->getTitleName().compare(gesture) == 0)
-				LL_COMPILE_TIME_MESSAGE("String view support detected, remove this macro check, this line and the old check below");
-#endif
-#endif
-				if (pPreview && pPreview->getTitleName() ==
-#ifndef LL_WINDOWS
-					static_cast<const std::string>(
-#endif
-					"Gesture"
-#ifndef LL_WINDOWS
-						)
-#endif
-					)
+				if (pPreview && std::string_view(pPreview->getTitleName()) == gesture)
 				{
 					wait_anim = pPreview->getChild<LLCheckBoxCtrl>("wait_anim_check")->getLabel();
 					break;