99 lines
3.1 KiB
C++
99 lines
3.1 KiB
C++
/* Copyright 2017 The TensorFlow Authors. All Rights Reserved.
|
|
|
|
Licensed under the Apache License, Version 2.0 (the "License");
|
|
you may not use this file except in compliance with the License.
|
|
You may obtain a copy of the License at
|
|
|
|
http://www.apache.org/licenses/LICENSE-2.0
|
|
|
|
Unless required by applicable law or agreed to in writing, software
|
|
distributed under the License is distributed on an "AS IS" BASIS,
|
|
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
See the License for the specific language governing permissions and
|
|
limitations under the License.
|
|
==============================================================================*/
|
|
|
|
#ifndef TENSORFLOW_COMPILER_XLA_ITERATOR_UTIL_H_
|
|
#define TENSORFLOW_COMPILER_XLA_ITERATOR_UTIL_H_
|
|
|
|
#include <iterator>
|
|
#include <utility>
|
|
|
|
namespace xla {
|
|
|
|
// UnwrappingIterator is a transforming iterator that calls get() on the
|
|
// elements it returns.
|
|
//
|
|
// Together with tensorflow::gtl::iterator_range, this lets classes which
|
|
// contain a collection of smart pointers expose a view of raw pointers to
|
|
// consumers. For example:
|
|
//
|
|
// class MyContainer {
|
|
// public:
|
|
// tensorflow::gtl::iterator_range<
|
|
// UnwrappingIterator<std::vector<std::unique_ptr<Thing>>::iterator>>
|
|
// things() {
|
|
// return {MakeUnwrappingIterator(things_.begin()),
|
|
// MakeUnwrappingIterator(things_.end())};
|
|
// }
|
|
//
|
|
// tensorflow::gtl::iterator_range<UnwrappingIterator<
|
|
// std::vector<std::unique_ptr<Thing>>::const_iterator>>
|
|
// things() const {
|
|
// return {MakeUnwrappingIterator(things_.begin()),
|
|
// MakeUnwrappingIterator(things_.end())};
|
|
// }
|
|
//
|
|
// private:
|
|
// std::vector<std::unique_ptr<Thing>> things_;
|
|
// };
|
|
//
|
|
// MyContainer container = ...;
|
|
// for (Thing* t : container.things()) {
|
|
// ...
|
|
// }
|
|
//
|
|
// For simplicity, UnwrappingIterator is currently unconditionally an
|
|
// input_iterator -- it doesn't inherit any superpowers NestedIterator may have.
|
|
template <typename NestedIter>
|
|
class UnwrappingIterator
|
|
: public std::iterator<std::input_iterator_tag,
|
|
decltype(std::declval<NestedIter>()->get())> {
|
|
private:
|
|
NestedIter iter_;
|
|
|
|
public:
|
|
explicit UnwrappingIterator(NestedIter iter) : iter_(std::move(iter)) {}
|
|
|
|
auto operator*() -> decltype(iter_->get()) { return iter_->get(); }
|
|
auto operator-> () -> decltype(iter_->get()) { return iter_->get(); }
|
|
UnwrappingIterator& operator++() {
|
|
++iter_;
|
|
return *this;
|
|
}
|
|
UnwrappingIterator operator++(int) {
|
|
UnwrappingIterator temp(iter_);
|
|
operator++();
|
|
return temp;
|
|
}
|
|
|
|
friend bool operator==(const UnwrappingIterator& a,
|
|
const UnwrappingIterator& b) {
|
|
return a.iter_ == b.iter_;
|
|
}
|
|
|
|
friend bool operator!=(const UnwrappingIterator& a,
|
|
const UnwrappingIterator& b) {
|
|
return !(a == b);
|
|
}
|
|
};
|
|
|
|
template <typename NestedIter>
|
|
UnwrappingIterator<NestedIter> MakeUnwrappingIterator(NestedIter iter) {
|
|
return UnwrappingIterator<NestedIter>(std::move(iter));
|
|
}
|
|
|
|
} // namespace xla
|
|
|
|
#endif // TENSORFLOW_COMPILER_XLA_ITERATOR_UTIL_H_
|