1 // Copyright 2022 The Pigweed Authors 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); you may not 4 // use this file except in compliance with the License. You may obtain a copy of 5 // the License at 6 // 7 // https://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 11 // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the 12 // License for the specific language governing permissions and limitations under 13 // the License. 14 #pragma once 15 16 #include <cstddef> 17 #include <iterator> 18 #include <utility> 19 20 namespace pw::containers::internal_algorithm { 21 22 // The type of the iterator given by begin(c) (possibly std::begin(c)). 23 // ContainerIter<const vector<T>> gives vector<T>::const_iterator, 24 // while ContainerIter<vector<T>> gives vector<T>::iterator. 25 template <typename C> 26 using ContainerIter = decltype(std::begin(std::declval<C&>())); 27 28 // An MSVC bug involving template parameter substitution requires us to use 29 // decltype() here instead of just std::pair. 30 template <typename C1, typename C2> 31 using ContainerIterPairType = 32 decltype(std::make_pair(ContainerIter<C1>(), ContainerIter<C2>())); 33 34 template <typename C> 35 using ContainerDifferenceType = decltype(std::distance( 36 std::declval<ContainerIter<C>>(), std::declval<ContainerIter<C>>())); 37 38 } // namespace pw::containers::internal_algorithm 39