From b0186e8878204a29e25ca4063c1dac4dea908508 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Sun, 19 Apr 2020 17:24:55 +0300
Subject: [PATCH] Support loader functions with bound first argument

This allows more flexibility in defining dynamic keywords.  Only
available with C++11.
---
 source/loader.h       |  8 ++++++++
 source/loaderaction.h | 27 +++++++++++++++++++++++++++
 2 files changed, 35 insertions(+)

diff --git a/source/loader.h b/source/loader.h
index 02caaaf..7799a7e 100644
--- a/source/loader.h
+++ b/source/loader.h
@@ -120,6 +120,14 @@ protected:
 	{ add(k, new LoaderFunc5<L, A0, A1, A2, A3, A4>(func)); }
 #endif
 
+#if __cplusplus>=201103L
+	/** Adds a keyword that is loaded by calling a function with a bound
+	first argument. */
+	template<typename L, typename B0, typename... Args>
+	void add(const std::string &k, void (L::*func)(B0, Args...), const typename RemoveReference<B0>::Type &b0)
+	{ add(k, new LoaderFuncNBound1<L, B0, Args...>(func, b0)); }
+#endif
+
 	/** Adds a keyword that is loaded into a member of the loaded object. */
 	template<typename L, typename T0>
 	void add(const std::string &k, T0 L::*p0)
diff --git a/source/loaderaction.h b/source/loaderaction.h
index 7e4feac..a3b0443 100644
--- a/source/loaderaction.h
+++ b/source/loaderaction.h
@@ -361,6 +361,33 @@ public:
 	{ return create_signature<Args...>(); }
 };
 
+
+template<typename L, typename B0, typename... Args>
+class LoaderFuncNBound1: public LoaderAction
+{
+protected:
+	typedef void (L::*FuncType)(B0, Args...);
+	typedef typename RemoveReference<B0>::Type Bound0Type;
+
+	FuncType func;
+	Bound0Type bound0;
+
+public:
+	LoaderFuncNBound1(FuncType f, const Bound0Type &b0): func(f), bound0(b0) { }
+
+	virtual void execute(Loader &l, const Statement &st) const
+	{
+		Apply<0, Args...>::apply(dynamic_cast<L &>(l), func, st, bound0);
+	}
+
+	virtual void execute(Loader &l, const ArgumentStore &as) const
+	{
+		Apply<0, Args...>::apply(dynamic_cast<L &>(l), func, as, bound0);
+	}
+
+	virtual std::string get_signature() const
+	{ return create_signature<Args...>(); }
+};
 #endif
 
 
-- 
2.43.0