#pragma once
+#include <array>
#include <functional>
#include <tuple>
+#include <type_traits>
+#include <utility>
+
+#include <QDebug>
+#include <QVariantList>
+
+// ---- Function traits --------------------------------------------------------------------------------------------------------------------
namespace detail {
*/
template<typename Callable>
using FunctionTraits = detail::FuncHelper<Callable>;
+
+// ---- Invoke function with argument list -------------------------------------------------------------------------------------------------
+
+namespace detail {
+
+// Helper for unpacking the argument list via an index sequence
+template<typename Callable, std::size_t ...Is, typename ArgsTuple = typename FunctionTraits<Callable>::ArgsTuple>
+bool invokeWithArgsList(const Callable& c, const QVariantList& args, std::index_sequence<Is...>)
+{
+ // Sanity check that all types can be converted
+ std::array<bool, std::tuple_size<ArgsTuple>::value> convertible{{args[Is].canConvert<std::decay_t<std::tuple_element_t<Is, ArgsTuple>>>()...}};
+ for (size_t i = 0; i < convertible.size(); ++i) {
+ if (!convertible[i]) {
+ qWarning() << "Cannot convert parameter" << i << "from type" << args[static_cast<int>(i)].typeName() << "to expected argument type";
+ return false;
+ }
+ }
+
+ // Invoke callable
+ c(args[Is].value<std::decay_t<std::tuple_element_t<Is, ArgsTuple>>>()...);
+ return true;
+}
+
+} // detail
+
+/**
+ * Invokes the given callable with the arguments contained in the given variant list.
+ *
+ * The types contained in the given QVariantList are converted to the types expected by the callable.
+ * If the conversion fails, or if the argument count does not match, this function returns false and
+ * the callable is not invoked.
+ *
+ * @param c Callable
+ * @param args Arguments to be given to the callable
+ * @returns true if the callable could be invoked with the given list of arguments
+ */
+template<typename Callable>
+bool invokeWithArgsList(const Callable& c, const QVariantList& args)
+{
+ using ArgsTuple = typename FunctionTraits<Callable>::ArgsTuple;
+ constexpr auto tupleSize = std::tuple_size<ArgsTuple>::value;
+
+ if (tupleSize != args.size()) {
+ qWarning().nospace() << "Argument count mismatch! Expected: " << tupleSize << ", actual: " << args.size();
+ return false;
+ }
+ return detail::invokeWithArgsList(c, args, std::make_index_sequence<tupleSize>{});
+}
--- /dev/null
+/***************************************************************************
+ * Copyright (C) 2005-2018 by the Quassel Project *
+ * devel@quassel-irc.org *
+ * *
+ * This program 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) version 3. *
+ * *
+ * This program 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 this program; if not, write to the *
+ * Free Software Foundation, Inc., *
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. *
+ ***************************************************************************/
+
+#include "testglobal.h"
+
+#include <QVariantList>
+
+#include "funchelpers.h"
+
+TEST(FuncHelpersTest, invokeWithArgsList)
+{
+ int intVal{};
+ QString stringVal{};
+
+ auto callable = [&intVal, &stringVal](int i, const QString& s)
+ {
+ intVal = i;
+ stringVal = s;
+ };
+
+ // Good case
+ {
+ QVariantList argsList{42, "Hello World"};
+ ASSERT_TRUE(invokeWithArgsList(callable, argsList));
+ EXPECT_EQ(42, intVal);
+ EXPECT_EQ("Hello World", stringVal);
+ }
+
+ // Too many arguments
+ {
+ QVariantList argsList{23, "Hi Universe", 2.3};
+ ASSERT_FALSE(invokeWithArgsList(callable, argsList));
+ // Values shouldn't have changed
+ EXPECT_EQ(42, intVal);
+ EXPECT_EQ("Hello World", stringVal);
+ }
+
+ // Too few arguments
+ {
+ QVariantList argsList{23};
+ ASSERT_FALSE(invokeWithArgsList(callable, argsList));
+ // Values shouldn't have changed
+ EXPECT_EQ(42, intVal);
+ EXPECT_EQ("Hello World", stringVal);
+ }
+
+ // Cannot convert argument type
+ {
+ // Ensure type cannot be converted
+ QVariantList wrong{"Foo", "Bar"};
+ QVariant v{wrong};
+ ASSERT_FALSE(v.canConvert<QString>());
+
+ QVariantList argsList{23, wrong};
+ ASSERT_FALSE(invokeWithArgsList(callable, argsList));
+ // Values shouldn't have changed
+ EXPECT_EQ(42, intVal);
+ EXPECT_EQ("Hello World", stringVal);
+ }
+}