Index: ps/trunk/source/scriptinterface/NativeWrapperDecls.h
===================================================================
--- ps/trunk/source/scriptinterface/NativeWrapperDecls.h	(revision 17702)
+++ ps/trunk/source/scriptinterface/NativeWrapperDecls.h	(revision 17703)
@@ -1,125 +1,123 @@
 /* Copyright (C) 2016 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation, either version 2 of the License, or
  * (at your option) any later version.
  *
  * 0 A.D. is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with 0 A.D.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 #include <boost/preprocessor/punctuation/comma_if.hpp>
 #include <boost/preprocessor/repetition/repeat.hpp>
 
-private:
-
-	template <typename T> struct MaybeRef;
-
-public:
+// MaybeRef should be private, but has to be public due to a compiler bug in clang.
+// TODO: Make this private when the bug is fixed in all supported versions of clang.
+template <typename T> struct MaybeRef;
 
 // Define lots of useful macros:
 
 // Varieties of comma-separated list to fit on the head/tail/whole of another comma-separated list
 #define NUMBERED_LIST_HEAD(z, i, data) data##i,
 #define NUMBERED_LIST_TAIL(z, i, data) ,data##i
 #define NUMBERED_LIST_TAIL_MAYBE_REF(z, i, data) , typename MaybeRef<data##i>::Type
 #define NUMBERED_LIST_BALANCED(z, i, data) BOOST_PP_COMMA_IF(i) data##i
 #define NUMBERED_LIST_BALANCED_MAYBE_REF(z, i, data) BOOST_PP_COMMA_IF(i) typename MaybeRef<data##i>::Type
 // Some other things
 #define TYPED_ARGS(z, i, data) , T##i a##i
 #define TYPED_ARGS_MAYBE_REF(z, i, data) , typename MaybeRef<T##i>::Type a##i
 #define TYPED_ARGS_CONST_REF(z, i, data) const T##i& a##i,
 
 // TODO: We allow optional parameters when the C++ type can be converted from JS::UndefinedValue.
 // FromJSVal is expected to either set a##i or return false (otherwise we could get undefined
 // behaviour because some types have undefined values when not being initialized).
 // This is not very clear and also a bit fragile. Another problem is that the error reporting lacks
 // a bit. SpiderMonkey will throw a JS exception and abort the execution of the current function when
 // we return false here (without printing a callstack or additional detail telling that an argument
 // conversion failed). So we have two TODOs here:
 // 1. On the conceptual side: How to consistently work with optional parameters (or drop them completely?)
 // 2. On the technical side: Improve error handling, find a better way to ensure parameters are initialized
 #define CONVERT_ARG(z, i, data) \
 	bool typeConvRet##i; \
 	T##i a##i = ScriptInterface::AssignOrFromJSVal<T##i>( \
 		cx, \
 		i < args.length() ? args[i] : JS::UndefinedHandleValue, \
 		typeConvRet##i); \
 	if (!typeConvRet##i) return false;
 
 // List-generating macros, named roughly after their first list item
 #define TYPENAME_T0_HEAD(z, i) BOOST_PP_REPEAT_##z (i, NUMBERED_LIST_HEAD, typename T) // "typename T0, typename T1, "
 #define TYPENAME_T0_TAIL(z, i) BOOST_PP_REPEAT_##z (i, NUMBERED_LIST_TAIL, typename T) // ", typename T0, typename T1"
 #define T0(z, i) BOOST_PP_REPEAT_##z (i, NUMBERED_LIST_BALANCED, T) // "T0, T1"
 #define T0_MAYBE_REF(z, i) BOOST_PP_REPEAT_##z (i, NUMBERED_LIST_BALANCED_MAYBE_REF, T) // "const T0&, T1"
 #define T0_HEAD(z, i) BOOST_PP_REPEAT_##z (i, NUMBERED_LIST_HEAD, T) // "T0, T1, "
 #define T0_TAIL(z, i) BOOST_PP_REPEAT_##z (i, NUMBERED_LIST_TAIL, T) // ", T0, T1"
 #define T0_TAIL_MAYBE_REF(z, i) BOOST_PP_REPEAT_##z (i, NUMBERED_LIST_TAIL_MAYBE_REF, T) // ", const T0&, T1"
 #define T0_A0(z, i) BOOST_PP_REPEAT_##z (i, TYPED_ARGS, ~) // ",T0 a0, T1 a1"
 #define T0_A0_MAYBE_REF(z, i) BOOST_PP_REPEAT_##z (i, TYPED_ARGS_MAYBE_REF, ~) // ",const T0& a0, T1 a1"
 #define T0_A0_CONST_REF(z, i) BOOST_PP_REPEAT_##z (i, TYPED_ARGS_CONST_REF, ~) // ", const T0& a0, const T1& a1, "
 #define A0(z, i) BOOST_PP_REPEAT_##z (i, NUMBERED_LIST_BALANCED, a) // "a0, a1"
 #define A0_TAIL(z, i) BOOST_PP_REPEAT_##z (i, NUMBERED_LIST_TAIL, a) // ", a0, a1"
 
 // Define RegisterFunction<TR, T0..., f>
 #define OVERLOADS(z, i, data) \
 	template <typename R, TYPENAME_T0_HEAD(z,i)  R (*fptr) ( ScriptInterface::CxPrivate* T0_TAIL_MAYBE_REF(z,i) )> \
 	void RegisterFunction(const char* name) { \
 		Register(name, call<R, T0_HEAD(z,i)  fptr>, nargs<0 T0_TAIL(z,i)>()); \
 	}
 BOOST_PP_REPEAT(SCRIPT_INTERFACE_MAX_ARGS, OVERLOADS, ~)
 #undef OVERLOADS
 
 // JSFastNative-compatible function that wraps the function identified in the template argument list
 // (Definition comes later, since it depends on some things we haven't defined yet)
 #define OVERLOADS(z, i, data) \
 	template <typename R, TYPENAME_T0_HEAD(z,i)  R (*fptr) ( ScriptInterface::CxPrivate* T0_TAIL_MAYBE_REF(z,i) )> \
 	static bool call(JSContext* cx, uint argc, jsval* vp);
 BOOST_PP_REPEAT(SCRIPT_INTERFACE_MAX_ARGS, OVERLOADS, ~)
 #undef OVERLOADS
 
 // Similar, for class methods
 #define OVERLOADS(z, i, data) \
 	template <typename R, TYPENAME_T0_HEAD(z,i)  JSClass* CLS, typename TC, R (TC::*fptr) ( T0_MAYBE_REF(z,i) )> \
 	static bool callMethod(JSContext* cx, uint argc, jsval* vp);
 BOOST_PP_REPEAT(SCRIPT_INTERFACE_MAX_ARGS, OVERLOADS, ~)
 #undef OVERLOADS
 
 // Argument-number counter
 #define OVERLOADS(z, i, data) \
 	template <int dummy TYPENAME_T0_TAIL(z,i)> /* add a dummy parameter so we still compile with 0 template args */ \
 	static size_t nargs() { return i; }
 BOOST_PP_REPEAT(SCRIPT_INTERFACE_MAX_ARGS, OVERLOADS, ~)
 #undef OVERLOADS
 
 // Call the named property on the given object
 #define OVERLOADS(z, i, data) \
 	template <typename R TYPENAME_T0_TAIL(z, i)> \
 	bool CallFunction(JS::HandleValue val, const char* name, T0_A0_CONST_REF(z,i) R& ret);
 BOOST_PP_REPEAT(SCRIPT_INTERFACE_MAX_ARGS, OVERLOADS, ~)
 #undef OVERLOADS
 
 // Implicit conversion from JS::Rooted<R>* to JS::MutableHandle<R> does not work with template argument deduction
 // (only exact type matches allowed). We need this overload to allow passing Rooted<R>* using the & operator
 // (as people would expect it to work based on the SpiderMonkey rooting guide).
 #define OVERLOADS(z, i, data) \
 	template <typename R TYPENAME_T0_TAIL(z, i)> \
 	bool CallFunction(JS::HandleValue val, const char* name, T0_A0_CONST_REF(z,i) JS::Rooted<R>* ret);
 BOOST_PP_REPEAT(SCRIPT_INTERFACE_MAX_ARGS, OVERLOADS, ~)
 #undef OVERLOADS
 
 // This overload is for the case when a JS::MutableHandle<R> type gets passed into CallFunction directly and
 // without requiring implicit conversion.
 #define OVERLOADS(z, i, data) \
 	template <typename R TYPENAME_T0_TAIL(z, i)> \
 	bool CallFunction(JS::HandleValue val, const char* name, T0_A0_CONST_REF(z,i) JS::MutableHandle<R> ret);
 BOOST_PP_REPEAT(SCRIPT_INTERFACE_MAX_ARGS, OVERLOADS, ~)
 #undef OVERLOADS