gras: created element factory

1 files changed, 85 insertions, 0 deletions

diff --git a/include/gras/factory.hpp b/include/gras/factory.hpp
new file mode 100644
index 0000000..926025e
--- /dev/null
+++ b/include/gras/factory.hpp
@@ -0,0 +1,85 @@
+// Copyright (C) by Josh Blum. See LICENSE.txt for licensing information.
+
+#ifndef INCLUDED_GRAS_FACTORY_HPP
+#define INCLUDED_GRAS_FACTORY_HPP
+
+#include <gras/gras.hpp>
+#include <gras/element.hpp>
+#include <PMC/PMC.hpp>
+#include <string>
+
+//! A fixture for static initialization code
+#define GRAS_STATIC_BLOCK(name) \
+    static struct name ## _static_fixture__ \
+    { \
+        name ## _static_fixture__(void); \
+    } name ## _static_fixture_instance__; \
+    name ## _static_fixture__::name ## _static_fixture__(void)
+
+/*!
+ * Register a block's factory function:
+ * Declare this macro at the global scope in a cpp file.
+ * The block will register at static initialization time.
+ */
+#define GRAS_REGISTER_FACTORY(name) \
+    GRAS_STATIC_BLOCK(name) \
+    {gras::Factory::register_make(#name, &name);}
+
+namespace gras
+{
+
+/*!
+ * Element factory:
+ *  - Register factory functions into the global factory.
+ *  - Call make() to create element from global factory.
+ *
+ * Example register a factory function:
+ *  gras::Factory::register_make("make_my_block", &make_my_block);
+ *
+ * Example call into the factory:
+ *  gras::Element *my_block = gras::Factory::make("make_my_block", arg0, arg1);
+ */
+class GRAS_API Factory : Callable
+{
+public:
+
+    /*******************************************************************
+     * Register API - don't look here, template magic, not helpful
+     ******************************************************************/
+    template <typename ReturnType>
+    static void register_make(const std::string &name, ReturnType(*fcn)(void));
+
+    template <typename ReturnType, typename Arg0>
+    static void register_make(const std::string &name, ReturnType(*fcn)(const Arg0 &));
+
+    template <typename ReturnType, typename Arg0, typename Arg1>
+    static void register_make(const std::string &name, ReturnType(*fcn)(const Arg0 &, const Arg1 &));
+
+    template <typename ReturnType, typename Arg0, typename Arg1, typename Arg2>
+    static void register_make(const std::string &name, ReturnType(*fcn)(const Arg0 &, const Arg1 &, const Arg2 &));
+
+    /*******************************************************************
+     * Make API - don't look here, template magic, not helpful
+     ******************************************************************/
+    inline
+    static Element *make(const std::string &name);
+
+    template <typename Arg0>
+    static Element *make(const std::string &name, const Arg0 &a0);
+
+    template <typename Arg0, typename Arg1>
+    static Element *make(const std::string &name, const Arg0 &a0, const Arg1 &a1);
+
+    template <typename Arg0, typename Arg1, typename Arg2>
+    static Element *make(const std::string &name, const Arg0 &a0, const Arg1 &a1, const Arg2 &a2);
+
+private:
+    static void _register_make(const std::string &, void *);
+    static Element *_make(const std::string &, const PMCC &);
+};
+
+}
+
+#include <gras/detail/factory.hpp>
+
+#endif /*INCLUDED_GRAS_FACTORY_HPP*/