Use variadic templates and forwarding references for better flexibility

[libs/datafile.git] / source / loader.h

diff --git a/source/loader.h b/source/loader.h
index 648c414cd2158b7d83983988f8027525b53940e6..b9eee50d8cde99b49fc897952580fa1d1695893e 100644 (file)
--- a/source/loader.h
+++ b/source/loader.h
@@ -85,10 +85,10 @@ protected:
        /** Loads a sub-object from the statement being processed with an extra
        parameter for the Loader.  The Loader class of the sub-object is
        automatically used. */
-       template<typename S, typename T>
-       void load_sub(S &s, T &p)
+       template<typename S, typename... Args>
+       void load_sub(S &s, Args &&... args)
        {
-               typename S::Loader ldr(s, p);
+               typename S::Loader ldr(s, std::forward<Args>(args)...);
                load_sub_with(ldr);
        }
 
@@ -119,6 +119,10 @@ protected:
        void add(const std::string &k, void (L::*func)(B0, Args...), const typename std::remove_reference<B0>::type &b0)
        { add(k, new LoaderFuncNBound1<L, B0, Args...>(func, b0)); }
 
+       template<typename L, typename B0, typename... Args>
+       void add(const std::string &k, void (L::*func)(B0, Args...), B0 &&b0)
+       { add(k, new LoaderFuncNBound1<L, B0, Args...>(func, std::forward<B0>(b0))); }
+
        /** 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)
@@ -161,12 +165,12 @@ Loads an object from a file.  The object must have a public Loader class.  Any
 extra arguments are passed to the Loader constructor.
 */
 template<typename T, typename... Args>
-void load(T &obj, const std::string &fn, Args &... args)
+void load(T &obj, const std::string &fn, Args &&... args)
 {
        IO::BufferedFile in(fn);
 
        Parser parser(in, fn);
-       typename T::Loader loader(obj, args...);
+       typename T::Loader loader(obj, std::forward<Args>(args)...);
        loader.load(parser);
 }
 
@@ -176,14 +180,14 @@ public Loader class.  The collection is passed to the Loader constructor,
 followed by any extra arguments.
 */
 template<typename T, typename... Args>
-void load(T &obj, typename T::Loader::Collection &coll, const std::string &fn, Args &... args)
+void load(T &obj, typename T::Loader::Collection &coll, const std::string &fn, Args &&... args)
 {
        RefPtr<IO::Seekable> in = coll.open_raw(fn);
        if(!in)
                throw IO::file_not_found(fn);
 
        Parser parser(*in, fn);
-       typename T::Loader loader(obj, coll, args...);
+       typename T::Loader loader(obj, coll, std::forward<Args>(args)...);
        loader.load(parser);
 }
 
@@ -192,14 +196,14 @@ Loads an object from a file stored in a collection.  The object must havea
 public Loader class.  Any extra arguments are passed to the Loader constructor.
 */
 template<typename T, typename C, typename... Args>
-typename std::enable_if<!NeedsCollection<typename T::Loader>::value>::type load(T &obj, C &coll, const std::string &fn, Args &... args)
+typename std::enable_if<!NeedsCollection<typename T::Loader>::value>::type load(T &obj, C &coll, const std::string &fn, Args &&... args)
 {
        RefPtr<IO::Seekable> in = coll.open_raw(fn);
        if(!in)
                throw IO::file_not_found(fn);
 
        Parser parser(*in, fn);
-       typename T::Loader loader(obj, args...);
+       typename T::Loader loader(obj, std::forward<Args>(args)...);
        loader.load(parser);
 }