Chris@50: // Copyright (c) 2013-2014 Sandstorm Development Group, Inc. and contributors
Chris@50: // Licensed under the MIT License:
Chris@50: //
Chris@50: // Permission is hereby granted, free of charge, to any person obtaining a copy
Chris@50: // of this software and associated documentation files (the "Software"), to deal
Chris@50: // in the Software without restriction, including without limitation the rights
Chris@50: // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
Chris@50: // copies of the Software, and to permit persons to whom the Software is
Chris@50: // furnished to do so, subject to the following conditions:
Chris@50: //
Chris@50: // The above copyright notice and this permission notice shall be included in
Chris@50: // all copies or substantial portions of the Software.
Chris@50: //
Chris@50: // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
Chris@50: // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
Chris@50: // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
Chris@50: // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
Chris@50: // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
Chris@50: // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
Chris@50: // THE SOFTWARE.
Chris@50: 
Chris@50: #ifndef CAPNP_LIST_H_
Chris@50: #define CAPNP_LIST_H_
Chris@50: 
Chris@50: #if defined(__GNUC__) && !defined(CAPNP_HEADER_WARNINGS)
Chris@50: #pragma GCC system_header
Chris@50: #endif
Chris@50: 
Chris@50: #include "layout.h"
Chris@50: #include "orphan.h"
Chris@50: #include <initializer_list>
Chris@50: #ifdef KJ_STD_COMPAT
Chris@50: #include <iterator>
Chris@50: #endif  // KJ_STD_COMPAT
Chris@50: 
Chris@50: namespace capnp {
Chris@50: namespace _ {  // private
Chris@50: 
Chris@50: template <typename T>
Chris@50: class TemporaryPointer {
Chris@50:   // This class is a little hack which lets us define operator->() in cases where it needs to
Chris@50:   // return a pointer to a temporary value.  We instead construct a TemporaryPointer and return that
Chris@50:   // (by value).  The compiler then invokes operator->() on the TemporaryPointer, which itself is
Chris@50:   // able to return a real pointer to its member.
Chris@50: 
Chris@50: public:
Chris@50:   TemporaryPointer(T&& value): value(kj::mv(value)) {}
Chris@50:   TemporaryPointer(const T& value): value(value) {}
Chris@50: 
Chris@50:   inline T* operator->() { return &value; }
Chris@50: private:
Chris@50:   T value;
Chris@50: };
Chris@50: 
Chris@50: template <typename Container, typename Element>
Chris@50: class IndexingIterator {
Chris@50: public:
Chris@50:   IndexingIterator() = default;
Chris@50: 
Chris@50:   inline Element operator*() const { return (*container)[index]; }
Chris@50:   inline TemporaryPointer<Element> operator->() const {
Chris@50:     return TemporaryPointer<Element>((*container)[index]);
Chris@50:   }
Chris@50:   inline Element operator[]( int off) const { return (*container)[index]; }
Chris@50:   inline Element operator[](uint off) const { return (*container)[index]; }
Chris@50: 
Chris@50:   inline IndexingIterator& operator++() { ++index; return *this; }
Chris@50:   inline IndexingIterator operator++(int) { IndexingIterator other = *this; ++index; return other; }
Chris@50:   inline IndexingIterator& operator--() { --index; return *this; }
Chris@50:   inline IndexingIterator operator--(int) { IndexingIterator other = *this; --index; return other; }
Chris@50: 
Chris@50:   inline IndexingIterator operator+(uint amount) const { return IndexingIterator(container, index + amount); }
Chris@50:   inline IndexingIterator operator-(uint amount) const { return IndexingIterator(container, index - amount); }
Chris@50:   inline IndexingIterator operator+( int amount) const { return IndexingIterator(container, index + amount); }
Chris@50:   inline IndexingIterator operator-( int amount) const { return IndexingIterator(container, index - amount); }
Chris@50: 
Chris@50:   inline int operator-(const IndexingIterator& other) const { return index - other.index; }
Chris@50: 
Chris@50:   inline IndexingIterator& operator+=(uint amount) { index += amount; return *this; }
Chris@50:   inline IndexingIterator& operator-=(uint amount) { index -= amount; return *this; }
Chris@50:   inline IndexingIterator& operator+=( int amount) { index += amount; return *this; }
Chris@50:   inline IndexingIterator& operator-=( int amount) { index -= amount; return *this; }
Chris@50: 
Chris@50:   // STL says comparing iterators of different containers is not allowed, so we only compare
Chris@50:   // indices here.
Chris@50:   inline bool operator==(const IndexingIterator& other) const { return index == other.index; }
Chris@50:   inline bool operator!=(const IndexingIterator& other) const { return index != other.index; }
Chris@50:   inline bool operator<=(const IndexingIterator& other) const { return index <= other.index; }
Chris@50:   inline bool operator>=(const IndexingIterator& other) const { return index >= other.index; }
Chris@50:   inline bool operator< (const IndexingIterator& other) const { return index <  other.index; }
Chris@50:   inline bool operator> (const IndexingIterator& other) const { return index >  other.index; }
Chris@50: 
Chris@50: private:
Chris@50:   Container* container;
Chris@50:   uint index;
Chris@50: 
Chris@50:   friend Container;
Chris@50:   inline IndexingIterator(Container* container, uint index)
Chris@50:       : container(container), index(index) {}
Chris@50: };
Chris@50: 
Chris@50: }  // namespace _ (private)
Chris@50: 
Chris@50: template <typename T>
Chris@50: struct List<T, Kind::PRIMITIVE> {
Chris@50:   // List of primitives.
Chris@50: 
Chris@50:   List() = delete;
Chris@50: 
Chris@50:   class Reader {
Chris@50:   public:
Chris@50:     typedef List<T> Reads;
Chris@50: 
Chris@50:     inline Reader(): reader(_::elementSizeForType<T>()) {}
Chris@50:     inline explicit Reader(_::ListReader reader): reader(reader) {}
Chris@50: 
Chris@50:     inline uint size() const { return reader.size() / ELEMENTS; }
Chris@50:     inline T operator[](uint index) const {
Chris@50:       KJ_IREQUIRE(index < size());
Chris@50:       return reader.template getDataElement<T>(index * ELEMENTS);
Chris@50:     }
Chris@50: 
Chris@50:     typedef _::IndexingIterator<const Reader, T> Iterator;
Chris@50:     inline Iterator begin() const { return Iterator(this, 0); }
Chris@50:     inline Iterator end() const { return Iterator(this, size()); }
Chris@50: 
Chris@50:   private:
Chris@50:     _::ListReader reader;
Chris@50:     template <typename U, Kind K>
Chris@50:     friend struct _::PointerHelpers;
Chris@50:     template <typename U, Kind K>
Chris@50:     friend struct List;
Chris@50:     friend class Orphanage;
Chris@50:     template <typename U, Kind K>
Chris@50:     friend struct ToDynamic_;
Chris@50:   };
Chris@50: 
Chris@50:   class Builder {
Chris@50:   public:
Chris@50:     typedef List<T> Builds;
Chris@50: 
Chris@50:     inline Builder(): builder(_::elementSizeForType<T>()) {}
Chris@50:     inline Builder(decltype(nullptr)) {}
Chris@50:     inline explicit Builder(_::ListBuilder builder): builder(builder) {}
Chris@50: 
Chris@50:     inline operator Reader() const { return Reader(builder.asReader()); }
Chris@50:     inline Reader asReader() const { return Reader(builder.asReader()); }
Chris@50: 
Chris@50:     inline uint size() const { return builder.size() / ELEMENTS; }
Chris@50:     inline T operator[](uint index) {
Chris@50:       KJ_IREQUIRE(index < size());
Chris@50:       return builder.template getDataElement<T>(index * ELEMENTS);
Chris@50:     }
Chris@50:     inline void set(uint index, T value) {
Chris@50:       // Alas, it is not possible to make operator[] return a reference to which you can assign,
Chris@50:       // since the encoded representation does not necessarily match the compiler's representation
Chris@50:       // of the type.  We can't even return a clever class that implements operator T() and
Chris@50:       // operator=() because it will lead to surprising behavior when using type inference (e.g.
Chris@50:       // calling a template function with inferred argument types, or using "auto" or "decltype").
Chris@50: 
Chris@50:       builder.template setDataElement<T>(index * ELEMENTS, value);
Chris@50:     }
Chris@50: 
Chris@50:     typedef _::IndexingIterator<Builder, T> Iterator;
Chris@50:     inline Iterator begin() { return Iterator(this, 0); }
Chris@50:     inline Iterator end() { return Iterator(this, size()); }
Chris@50: 
Chris@50:   private:
Chris@50:     _::ListBuilder builder;
Chris@50:     template <typename U, Kind K>
Chris@50:     friend struct _::PointerHelpers;
Chris@50:     friend class Orphanage;
Chris@50:     template <typename U, Kind K>
Chris@50:     friend struct ToDynamic_;
Chris@50:   };
Chris@50: 
Chris@50:   class Pipeline {};
Chris@50: 
Chris@50: private:
Chris@50:   inline static _::ListBuilder initPointer(_::PointerBuilder builder, uint size) {
Chris@50:     return builder.initList(_::elementSizeForType<T>(), size * ELEMENTS);
Chris@50:   }
Chris@50:   inline static _::ListBuilder getFromPointer(_::PointerBuilder builder, const word* defaultValue) {
Chris@50:     return builder.getList(_::elementSizeForType<T>(), defaultValue);
Chris@50:   }
Chris@50:   inline static _::ListReader getFromPointer(
Chris@50:       const _::PointerReader& reader, const word* defaultValue) {
Chris@50:     return reader.getList(_::elementSizeForType<T>(), defaultValue);
Chris@50:   }
Chris@50: 
Chris@50:   template <typename U, Kind k>
Chris@50:   friend struct List;
Chris@50:   template <typename U, Kind K>
Chris@50:   friend struct _::PointerHelpers;
Chris@50: };
Chris@50: 
Chris@50: template <typename T>
Chris@50: struct List<T, Kind::ENUM>: public List<T, Kind::PRIMITIVE> {};
Chris@50: 
Chris@50: template <typename T>
Chris@50: struct List<T, Kind::STRUCT> {
Chris@50:   // List of structs.
Chris@50: 
Chris@50:   List() = delete;
Chris@50: 
Chris@50:   class Reader {
Chris@50:   public:
Chris@50:     typedef List<T> Reads;
Chris@50: 
Chris@50:     inline Reader(): reader(ElementSize::INLINE_COMPOSITE) {}
Chris@50:     inline explicit Reader(_::ListReader reader): reader(reader) {}
Chris@50: 
Chris@50:     inline uint size() const { return reader.size() / ELEMENTS; }
Chris@50:     inline typename T::Reader operator[](uint index) const {
Chris@50:       KJ_IREQUIRE(index < size());
Chris@50:       return typename T::Reader(reader.getStructElement(index * ELEMENTS));
Chris@50:     }
Chris@50: 
Chris@50:     typedef _::IndexingIterator<const Reader, typename T::Reader> Iterator;
Chris@50:     inline Iterator begin() const { return Iterator(this, 0); }
Chris@50:     inline Iterator end() const { return Iterator(this, size()); }
Chris@50: 
Chris@50:   private:
Chris@50:     _::ListReader reader;
Chris@50:     template <typename U, Kind K>
Chris@50:     friend struct _::PointerHelpers;
Chris@50:     template <typename U, Kind K>
Chris@50:     friend struct List;
Chris@50:     friend class Orphanage;
Chris@50:     template <typename U, Kind K>
Chris@50:     friend struct ToDynamic_;
Chris@50:   };
Chris@50: 
Chris@50:   class Builder {
Chris@50:   public:
Chris@50:     typedef List<T> Builds;
Chris@50: 
Chris@50:     inline Builder(): builder(ElementSize::INLINE_COMPOSITE) {}
Chris@50:     inline Builder(decltype(nullptr)) {}
Chris@50:     inline explicit Builder(_::ListBuilder builder): builder(builder) {}
Chris@50: 
Chris@50:     inline operator Reader() const { return Reader(builder.asReader()); }
Chris@50:     inline Reader asReader() const { return Reader(builder.asReader()); }
Chris@50: 
Chris@50:     inline uint size() const { return builder.size() / ELEMENTS; }
Chris@50:     inline typename T::Builder operator[](uint index) {
Chris@50:       KJ_IREQUIRE(index < size());
Chris@50:       return typename T::Builder(builder.getStructElement(index * ELEMENTS));
Chris@50:     }
Chris@50: 
Chris@50:     inline void adoptWithCaveats(uint index, Orphan<T>&& orphan) {
Chris@50:       // Mostly behaves like you'd expect `adopt` to behave, but with two caveats originating from
Chris@50:       // the fact that structs in a struct list are allocated inline rather than by pointer:
Chris@50:       // * This actually performs a shallow copy, effectively adopting each of the orphan's
Chris@50:       //   children rather than adopting the orphan itself.  The orphan ends up being discarded,
Chris@50:       //   possibly wasting space in the message object.
Chris@50:       // * If the orphan is larger than the target struct -- say, because the orphan was built
Chris@50:       //   using a newer version of the schema that has additional fields -- it will be truncated,
Chris@50:       //   losing data.
Chris@50: 
Chris@50:       KJ_IREQUIRE(index < size());
Chris@50: 
Chris@50:       // We pass a zero-valued StructSize to asStruct() because we do not want the struct to be
Chris@50:       // expanded under any circumstances.  We're just going to throw it away anyway, and
Chris@50:       // transferContentFrom() already carefully compares the struct sizes before transferring.
Chris@50:       builder.getStructElement(index * ELEMENTS).transferContentFrom(
Chris@50:           orphan.builder.asStruct(_::StructSize(0 * WORDS, 0 * POINTERS)));
Chris@50:     }
Chris@50:     inline void setWithCaveats(uint index, const typename T::Reader& reader) {
Chris@50:       // Mostly behaves like you'd expect `set` to behave, but with a caveat originating from
Chris@50:       // the fact that structs in a struct list are allocated inline rather than by pointer:
Chris@50:       // If the source struct is larger than the target struct -- say, because the source was built
Chris@50:       // using a newer version of the schema that has additional fields -- it will be truncated,
Chris@50:       // losing data.
Chris@50:       //
Chris@50:       // Note: If you are trying to concatenate some lists, use Orphanage::newOrphanConcat() to
Chris@50:       //   do it without losing any data in case the source lists come from a newer version of the
Chris@50:       //   protocol. (Plus, it's easier to use anyhow.)
Chris@50: 
Chris@50:       KJ_IREQUIRE(index < size());
Chris@50:       builder.getStructElement(index * ELEMENTS).copyContentFrom(reader._reader);
Chris@50:     }
Chris@50: 
Chris@50:     // There are no init(), set(), adopt(), or disown() methods for lists of structs because the
Chris@50:     // elements of the list are inlined and are initialized when the list is initialized.  This
Chris@50:     // means that init() would be redundant, and set() would risk data loss if the input struct
Chris@50:     // were from a newer version of the protocol.
Chris@50: 
Chris@50:     typedef _::IndexingIterator<Builder, typename T::Builder> Iterator;
Chris@50:     inline Iterator begin() { return Iterator(this, 0); }
Chris@50:     inline Iterator end() { return Iterator(this, size()); }
Chris@50: 
Chris@50:   private:
Chris@50:     _::ListBuilder builder;
Chris@50:     template <typename U, Kind K>
Chris@50:     friend struct _::PointerHelpers;
Chris@50:     friend class Orphanage;
Chris@50:     template <typename U, Kind K>
Chris@50:     friend struct ToDynamic_;
Chris@50:   };
Chris@50: 
Chris@50:   class Pipeline {};
Chris@50: 
Chris@50: private:
Chris@50:   inline static _::ListBuilder initPointer(_::PointerBuilder builder, uint size) {
Chris@50:     return builder.initStructList(size * ELEMENTS, _::structSize<T>());
Chris@50:   }
Chris@50:   inline static _::ListBuilder getFromPointer(_::PointerBuilder builder, const word* defaultValue) {
Chris@50:     return builder.getStructList(_::structSize<T>(), defaultValue);
Chris@50:   }
Chris@50:   inline static _::ListReader getFromPointer(
Chris@50:       const _::PointerReader& reader, const word* defaultValue) {
Chris@50:     return reader.getList(ElementSize::INLINE_COMPOSITE, defaultValue);
Chris@50:   }
Chris@50: 
Chris@50:   template <typename U, Kind k>
Chris@50:   friend struct List;
Chris@50:   template <typename U, Kind K>
Chris@50:   friend struct _::PointerHelpers;
Chris@50: };
Chris@50: 
Chris@50: template <typename T>
Chris@50: struct List<List<T>, Kind::LIST> {
Chris@50:   // List of lists.
Chris@50: 
Chris@50:   List() = delete;
Chris@50: 
Chris@50:   class Reader {
Chris@50:   public:
Chris@50:     typedef List<List<T>> Reads;
Chris@50: 
Chris@50:     inline Reader(): reader(ElementSize::POINTER) {}
Chris@50:     inline explicit Reader(_::ListReader reader): reader(reader) {}
Chris@50: 
Chris@50:     inline uint size() const { return reader.size() / ELEMENTS; }
Chris@50:     inline typename List<T>::Reader operator[](uint index) const {
Chris@50:       KJ_IREQUIRE(index < size());
Chris@50:       return typename List<T>::Reader(
Chris@50:           _::PointerHelpers<List<T>>::get(reader.getPointerElement(index * ELEMENTS)));
Chris@50:     }
Chris@50: 
Chris@50:     typedef _::IndexingIterator<const Reader, typename List<T>::Reader> Iterator;
Chris@50:     inline Iterator begin() const { return Iterator(this, 0); }
Chris@50:     inline Iterator end() const { return Iterator(this, size()); }
Chris@50: 
Chris@50:   private:
Chris@50:     _::ListReader reader;
Chris@50:     template <typename U, Kind K>
Chris@50:     friend struct _::PointerHelpers;
Chris@50:     template <typename U, Kind K>
Chris@50:     friend struct List;
Chris@50:     friend class Orphanage;
Chris@50:     template <typename U, Kind K>
Chris@50:     friend struct ToDynamic_;
Chris@50:   };
Chris@50: 
Chris@50:   class Builder {
Chris@50:   public:
Chris@50:     typedef List<List<T>> Builds;
Chris@50: 
Chris@50:     inline Builder(): builder(ElementSize::POINTER) {}
Chris@50:     inline Builder(decltype(nullptr)) {}
Chris@50:     inline explicit Builder(_::ListBuilder builder): builder(builder) {}
Chris@50: 
Chris@50:     inline operator Reader() const { return Reader(builder.asReader()); }
Chris@50:     inline Reader asReader() const { return Reader(builder.asReader()); }
Chris@50: 
Chris@50:     inline uint size() const { return builder.size() / ELEMENTS; }
Chris@50:     inline typename List<T>::Builder operator[](uint index) {
Chris@50:       KJ_IREQUIRE(index < size());
Chris@50:       return typename List<T>::Builder(
Chris@50:           _::PointerHelpers<List<T>>::get(builder.getPointerElement(index * ELEMENTS)));
Chris@50:     }
Chris@50:     inline typename List<T>::Builder init(uint index, uint size) {
Chris@50:       KJ_IREQUIRE(index < this->size());
Chris@50:       return typename List<T>::Builder(
Chris@50:           _::PointerHelpers<List<T>>::init(builder.getPointerElement(index * ELEMENTS), size));
Chris@50:     }
Chris@50:     inline void set(uint index, typename List<T>::Reader value) {
Chris@50:       KJ_IREQUIRE(index < size());
Chris@50:       builder.getPointerElement(index * ELEMENTS).setList(value.reader);
Chris@50:     }
Chris@50:     void set(uint index, std::initializer_list<ReaderFor<T>> value) {
Chris@50:       KJ_IREQUIRE(index < size());
Chris@50:       auto l = init(index, value.size());
Chris@50:       uint i = 0;
Chris@50:       for (auto& element: value) {
Chris@50:         l.set(i++, element);
Chris@50:       }
Chris@50:     }
Chris@50:     inline void adopt(uint index, Orphan<T>&& value) {
Chris@50:       KJ_IREQUIRE(index < size());
Chris@50:       builder.getPointerElement(index * ELEMENTS).adopt(kj::mv(value.builder));
Chris@50:     }
Chris@50:     inline Orphan<T> disown(uint index) {
Chris@50:       KJ_IREQUIRE(index < size());
Chris@50:       return Orphan<T>(builder.getPointerElement(index * ELEMENTS).disown());
Chris@50:     }
Chris@50: 
Chris@50:     typedef _::IndexingIterator<Builder, typename List<T>::Builder> Iterator;
Chris@50:     inline Iterator begin() { return Iterator(this, 0); }
Chris@50:     inline Iterator end() { return Iterator(this, size()); }
Chris@50: 
Chris@50:   private:
Chris@50:     _::ListBuilder builder;
Chris@50:     template <typename U, Kind K>
Chris@50:     friend struct _::PointerHelpers;
Chris@50:     friend class Orphanage;
Chris@50:     template <typename U, Kind K>
Chris@50:     friend struct ToDynamic_;
Chris@50:   };
Chris@50: 
Chris@50:   class Pipeline {};
Chris@50: 
Chris@50: private:
Chris@50:   inline static _::ListBuilder initPointer(_::PointerBuilder builder, uint size) {
Chris@50:     return builder.initList(ElementSize::POINTER, size * ELEMENTS);
Chris@50:   }
Chris@50:   inline static _::ListBuilder getFromPointer(_::PointerBuilder builder, const word* defaultValue) {
Chris@50:     return builder.getList(ElementSize::POINTER, defaultValue);
Chris@50:   }
Chris@50:   inline static _::ListReader getFromPointer(
Chris@50:       const _::PointerReader& reader, const word* defaultValue) {
Chris@50:     return reader.getList(ElementSize::POINTER, defaultValue);
Chris@50:   }
Chris@50: 
Chris@50:   template <typename U, Kind k>
Chris@50:   friend struct List;
Chris@50:   template <typename U, Kind K>
Chris@50:   friend struct _::PointerHelpers;
Chris@50: };
Chris@50: 
Chris@50: template <typename T>
Chris@50: struct List<T, Kind::BLOB> {
Chris@50:   List() = delete;
Chris@50: 
Chris@50:   class Reader {
Chris@50:   public:
Chris@50:     typedef List<T> Reads;
Chris@50: 
Chris@50:     inline Reader(): reader(ElementSize::POINTER) {}
Chris@50:     inline explicit Reader(_::ListReader reader): reader(reader) {}
Chris@50: 
Chris@50:     inline uint size() const { return reader.size() / ELEMENTS; }
Chris@50:     inline typename T::Reader operator[](uint index) const {
Chris@50:       KJ_IREQUIRE(index < size());
Chris@50:       return reader.getPointerElement(index * ELEMENTS).template getBlob<T>(nullptr, 0 * BYTES);
Chris@50:     }
Chris@50: 
Chris@50:     typedef _::IndexingIterator<const Reader, typename T::Reader> Iterator;
Chris@50:     inline Iterator begin() const { return Iterator(this, 0); }
Chris@50:     inline Iterator end() const { return Iterator(this, size()); }
Chris@50: 
Chris@50:   private:
Chris@50:     _::ListReader reader;
Chris@50:     template <typename U, Kind K>
Chris@50:     friend struct _::PointerHelpers;
Chris@50:     template <typename U, Kind K>
Chris@50:     friend struct List;
Chris@50:     friend class Orphanage;
Chris@50:     template <typename U, Kind K>
Chris@50:     friend struct ToDynamic_;
Chris@50:   };
Chris@50: 
Chris@50:   class Builder {
Chris@50:   public:
Chris@50:     typedef List<T> Builds;
Chris@50: 
Chris@50:     inline Builder(): builder(ElementSize::POINTER) {}
Chris@50:     inline Builder(decltype(nullptr)) {}
Chris@50:     inline explicit Builder(_::ListBuilder builder): builder(builder) {}
Chris@50: 
Chris@50:     inline operator Reader() const { return Reader(builder.asReader()); }
Chris@50:     inline Reader asReader() const { return Reader(builder.asReader()); }
Chris@50: 
Chris@50:     inline uint size() const { return builder.size() / ELEMENTS; }
Chris@50:     inline typename T::Builder operator[](uint index) {
Chris@50:       KJ_IREQUIRE(index < size());
Chris@50:       return builder.getPointerElement(index * ELEMENTS).template getBlob<T>(nullptr, 0 * BYTES);
Chris@50:     }
Chris@50:     inline void set(uint index, typename T::Reader value) {
Chris@50:       KJ_IREQUIRE(index < size());
Chris@50:       builder.getPointerElement(index * ELEMENTS).template setBlob<T>(value);
Chris@50:     }
Chris@50:     inline typename T::Builder init(uint index, uint size) {
Chris@50:       KJ_IREQUIRE(index < this->size());
Chris@50:       return builder.getPointerElement(index * ELEMENTS).template initBlob<T>(size * BYTES);
Chris@50:     }
Chris@50:     inline void adopt(uint index, Orphan<T>&& value) {
Chris@50:       KJ_IREQUIRE(index < size());
Chris@50:       builder.getPointerElement(index * ELEMENTS).adopt(kj::mv(value.builder));
Chris@50:     }
Chris@50:     inline Orphan<T> disown(uint index) {
Chris@50:       KJ_IREQUIRE(index < size());
Chris@50:       return Orphan<T>(builder.getPointerElement(index * ELEMENTS).disown());
Chris@50:     }
Chris@50: 
Chris@50:     typedef _::IndexingIterator<Builder, typename T::Builder> Iterator;
Chris@50:     inline Iterator begin() { return Iterator(this, 0); }
Chris@50:     inline Iterator end() { return Iterator(this, size()); }
Chris@50: 
Chris@50:   private:
Chris@50:     _::ListBuilder builder;
Chris@50:     template <typename U, Kind K>
Chris@50:     friend struct _::PointerHelpers;
Chris@50:     friend class Orphanage;
Chris@50:     template <typename U, Kind K>
Chris@50:     friend struct ToDynamic_;
Chris@50:   };
Chris@50: 
Chris@50:   class Pipeline {};
Chris@50: 
Chris@50: private:
Chris@50:   inline static _::ListBuilder initPointer(_::PointerBuilder builder, uint size) {
Chris@50:     return builder.initList(ElementSize::POINTER, size * ELEMENTS);
Chris@50:   }
Chris@50:   inline static _::ListBuilder getFromPointer(_::PointerBuilder builder, const word* defaultValue) {
Chris@50:     return builder.getList(ElementSize::POINTER, defaultValue);
Chris@50:   }
Chris@50:   inline static _::ListReader getFromPointer(
Chris@50:       const _::PointerReader& reader, const word* defaultValue) {
Chris@50:     return reader.getList(ElementSize::POINTER, defaultValue);
Chris@50:   }
Chris@50: 
Chris@50:   template <typename U, Kind k>
Chris@50:   friend struct List;
Chris@50:   template <typename U, Kind K>
Chris@50:   friend struct _::PointerHelpers;
Chris@50: };
Chris@50: 
Chris@50: }  // namespace capnp
Chris@50: 
Chris@50: #ifdef KJ_STD_COMPAT
Chris@50: namespace std {
Chris@50: 
Chris@50: template <typename Container, typename Element>
Chris@50: struct iterator_traits<capnp::_::IndexingIterator<Container, Element>>
Chris@50:       : public std::iterator<std::random_access_iterator_tag, Element, int> {};
Chris@50: 
Chris@50: }  // namespace std
Chris@50: #endif  // KJ_STD_COMPAT
Chris@50: 
Chris@50: #endif  // CAPNP_LIST_H_