1 /* 2 * Copyright 2014 Google Inc. All rights reserved. 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef FRUIT_CALL_WITH_TUPLE_H 18 #define FRUIT_CALL_WITH_TUPLE_H 19 20 #include <fruit/impl/meta/vector.h> 21 22 namespace fruit { 23 namespace impl { 24 25 template <typename IntVector, typename Result, typename ArgsTuple> 26 struct CallWithTupleHelper; 27 28 template <typename... Ints, typename Result, typename... Args> 29 struct CallWithTupleHelper<fruit::impl::meta::Vector<Ints...>, Result, std::tuple<Args...>> { 30 Result operator()(Result (*fun)(Args...), std::tuple<Args...> args) { 31 // This parameter *is* used, but when the tuple is empty some compilers report is as unused. 32 (void)args; 33 return fun(std::get<fruit::impl::meta::getIntValue<Ints>()>(args)...); 34 } 35 }; 36 37 template <typename Result, typename... Args> 38 inline Result callWithTuple(Result (*fun)(Args...), std::tuple<Args...> args) { 39 using IntVector = 40 fruit::impl::meta::Eval<fruit::impl::meta::GenerateIntSequence(fruit::impl::meta::Int<sizeof...(Args)>)>; 41 return CallWithTupleHelper<IntVector, Result, std::tuple<Args...>>()(fun, args); 42 } 43 } 44 } 45 46 #endif // FRUIT_CALL_WITH_TUPLE_H 47