17ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski/* 27ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski * Copyright (C) 2015 The Android Open Source Project 37ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski * 47ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski * Licensed under the Apache License, Version 2.0 (the "License"); 57ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski * you may not use this file except in compliance with the License. 67ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski * You may obtain a copy of the License at 77ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski * 87ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski * http://www.apache.org/licenses/LICENSE-2.0 97ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski * 107ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski * Unless required by applicable law or agreed to in writing, software 117ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski * distributed under the License is distributed on an "AS IS" BASIS, 127ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 137ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski * See the License for the specific language governing permissions and 147ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski * limitations under the License. 157ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski */ 167ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski 177ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski#ifndef AAPT_UTIL_TYPETRAITS_H 187ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski#define AAPT_UTIL_TYPETRAITS_H 197ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski 207ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski#include <type_traits> 217ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski 227ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinskinamespace aapt { 237ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski 247ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski#define DEFINE_HAS_BINARY_OP_TRAIT(name, op) \ 257ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski template <typename T, typename U> \ 267ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski struct name { \ 277ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski template <typename V, typename W> \ 287ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski static constexpr decltype(std::declval<V>() op std::declval<W>(), bool()) test(int) { \ 297ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski return true; \ 307ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski } \ 317ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski template <typename V, typename W> \ 327ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski static constexpr bool test(...) { \ 337ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski return false; \ 347ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski } \ 357ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski static constexpr bool value = test<T, U>(int()); \ 367ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski} 377ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski 387ff3ee19f4b831a526baf4b928d1ac172d070d82Adam LesinskiDEFINE_HAS_BINARY_OP_TRAIT(has_eq_op, ==); 397ff3ee19f4b831a526baf4b928d1ac172d070d82Adam LesinskiDEFINE_HAS_BINARY_OP_TRAIT(has_lt_op, <); 407ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski 417ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski/** 427ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski * Type trait that checks if two types can be equated (==) and compared (<). 437ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski */ 447ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinskitemplate <typename T, typename U> 457ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinskistruct is_comparable { 467ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski static constexpr bool value = has_eq_op<T, U>::value && has_lt_op<T, U>::value; 477ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski}; 487ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski 497ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski} // namespace aapt 507ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski 517ff3ee19f4b831a526baf4b928d1ac172d070d82Adam Lesinski#endif /* AAPT_UTIL_TYPETRAITS_H */ 52