Automated merge with ssh://bitbucket.org/rider_linden/azumarill-vivox

1 files changed, 63 insertions, 0 deletions

diff --git a/indra/llcommon/llmake.h b/indra/llcommon/llmake.h
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+/**
+ * @file   llmake.h
+ * @author Nat Goodspeed
+ * @date   2015-12-18
+ * @brief  Generic llmake<Template>(arg) function to instantiate
+ *         Template<decltype(arg)>(arg).
+ *
+ *         Many of our class templates have an accompanying helper function to
+ *         make an instance with arguments of arbitrary type. llmake()
+ *         eliminates the need to declare a new helper function for every such
+ *         class template.
+ * 
+ *         also relevant:
+ *
+ *         Template parameter deduction for constructors
+ *         http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0091r0.html
+ *
+ *         https://github.com/viboes/std-make
+ *
+ *         but obviously we're not there yet.
+ *
+ * $LicenseInfo:firstyear=2015&license=viewerlgpl$
+ * Copyright (c) 2015, Linden Research, Inc.
+ * $/LicenseInfo$
+ */
+
+#if ! defined(LL_LLMAKE_H)
+#define LL_LLMAKE_H
+
+/*==========================================================================*|
+// When we allow ourselves to compile with C++11 features enabled, this form
+// should generically handle an arbitrary number of arguments.
+
+template <template<typename...> class CLASS_TEMPLATE, typename... ARGS>
+CLASS_TEMPLATE<ARGS...> llmake(ARGS && ... args)
+{
+    return CLASS_TEMPLATE<ARGS...>(std::forward<ARGS>(args)...);
+}
+|*==========================================================================*/
+
+// As of 2015-12-18, this is what we'll use instead. Add explicit overloads
+// for different numbers of template parameters as use cases arise.
+
+/**
+ * Usage: llmake<SomeTemplate>(arg)
+ *
+ * Deduces the type T of 'arg' and returns an instance of SomeTemplate<T>
+ * initialized with 'arg'. Assumes a constructor accepting T (by value,
+ * reference or whatever).
+ */
+template <template<typename> class CLASS_TEMPLATE, typename ARG1>
+CLASS_TEMPLATE<ARG1> llmake(const ARG1& arg1)
+{
+    return CLASS_TEMPLATE<ARG1>(arg1);
+}
+
+template <template<typename, typename> class CLASS_TEMPLATE, typename ARG1, typename ARG2>
+CLASS_TEMPLATE<ARG1, ARG2> llmake(const ARG1& arg1, const ARG2& arg2)
+{
+    return CLASS_TEMPLATE<ARG1, ARG2>(arg1, arg2);
+}
+
+#endif /* ! defined(LL_LLMAKE_H) */