From 2846637f95cb757529aaff43f2df889f632a18ec Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=B6nke=20Ludwig?= <sludwig@rejectedsoftware.com>
Date: Mon, 24 Oct 2016 00:12:35 +0200
Subject: [PATCH] Add AlgebraicChoppedVector as the future base for the event
 drivers FD map.

---
 dub.sdl                                     |  2 +
 source/eventcore/internal/consumablequeue.d |  2 +-
 source/eventcore/internal/utils.d           | 41 +++++++++++++++++++++
 3 files changed, 44 insertions(+), 1 deletion(-)

diff --git a/dub.sdl b/dub.sdl
index c50b3a0..97dea66 100644
--- a/dub.sdl
+++ b/dub.sdl
@@ -8,6 +8,8 @@ targetType "library"
 libs "anl" platform="linux"
 libs "ws2_32" platform="windows"
 
+dependency "taggedalgebraic" version="~>0.10.4"
+
 configuration "epoll" {
 	platforms "linux"
 	versions "EventcoreEpollDriver"
diff --git a/source/eventcore/internal/consumablequeue.d b/source/eventcore/internal/consumablequeue.d
index 808d5c3..95289b9 100644
--- a/source/eventcore/internal/consumablequeue.d
+++ b/source/eventcore/internal/consumablequeue.d
@@ -2,7 +2,7 @@ module eventcore.internal.consumablequeue;
 
 /** FIFO queue with support for chunk-wise consumption.
 */
-class ConsumableQueue(T)
+final class ConsumableQueue(T)
 {
 	@safe:
 	nothrow:
diff --git a/source/eventcore/internal/utils.d b/source/eventcore/internal/utils.d
index 0ae0245..352edca 100644
--- a/source/eventcore/internal/utils.d
+++ b/source/eventcore/internal/utils.d
@@ -1,4 +1,8 @@
 module eventcore.internal.utils;
+
+import taggedalgebraic;
+
+
 void print(ARGS...)(string str, ARGS args)
 @trusted @nogc nothrow {
 	import std.format : formattedWrite;
@@ -120,6 +124,43 @@ struct ChoppedVector(T, size_t CHUNK_SIZE = 16*64*1024/nextPOT(T.sizeof)) {
 	}
 }
 
+struct AlgebraicChoppedVector(TCommon, TSpecific...)
+{
+	import std.conv : to;
+	import std.meta : AliasSeq;
+
+	union U { mixin fields!0; }
+	alias FieldType = TaggedAlgebraic!U;
+	static struct FullField {
+		TCommon common;
+		FieldType specific;
+		mixin(accessors());
+	}
+
+	ChoppedVector!(FullField) items;
+
+	alias items this;
+
+	private static string accessors()
+	{
+		import std.format : format;
+		string ret;
+		foreach (i, U; TSpecific)
+			ret ~= "@property ref TSpecific[%s] %s() nothrow @safe { return this.specific.get!(TSpecific[%s]); }\n"
+				.format(i, U.Handle.name, i);
+		return ret;
+	}
+
+	private mixin template fields(size_t i) {
+		static if (i < TSpecific.length) {
+			mixin("TSpecific["~i.to!string~"] "~TSpecific[i].Handle.name~";");
+			mixin fields!(i+1);
+		}
+	}
+}
+
+
+
 /** Efficient bit set of dynamic size.
 */
 struct SmallIntegerSet(V : uint)