From 8ba825d3ddb089e4e4fd651a36281e3c47cc9628 Mon Sep 17 00:00:00 2001
From: Paul Fd <paul@ferrand.cc>
Date: Wed, 11 Mar 2020 09:50:04 +0100
Subject: [PATCH] Clean up changes to the atomic_queue

---
 src/external/atomic_queue/atomic_queue.h | 30 ++++++++++++++++++++----
 1 file changed, 25 insertions(+), 5 deletions(-)

diff --git a/src/external/atomic_queue/atomic_queue.h b/src/external/atomic_queue/atomic_queue.h
index bcbd29a9..e7bcf0f2 100644
--- a/src/external/atomic_queue/atomic_queue.h
+++ b/src/external/atomic_queue/atomic_queue.h
@@ -95,15 +95,35 @@ constexpr T& map(T* elements, unsigned index) noexcept {
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 
+// Implement a "bit-twiddling hack" for finding the next power of 2
+// in either 32 bits or 64 bits in C++11 compatible constexpr functions
+
+// "Runtime" version for 32 bits
+// --a;
+// a |= a >> 1;
+// a |= a >> 2;
+// a |= a >> 4;
+// a |= a >> 8;
+// a |= a >> 16;
+// ++a;
+
 template<class T>
-constexpr T decrement(T x) { return x - 1; }
+constexpr T decrement(T x) {
+    return x - 1;
+}
+
 template<class T>
-constexpr T increment(T x) { return x + 1; }
+constexpr T increment(T x) {
+    return x + 1;
+}
+
 template<class T>
-constexpr T or_equal(T x, unsigned u) { return (x | x >> u); }
+constexpr T or_equal(T x, unsigned u) {
+    return (x | x >> u);
+}
+
 template<class T, class... Args>
-constexpr T or_equal(T x, unsigned u, Args... rest)
-{
+constexpr T or_equal(T x, unsigned u, Args... rest) {
     return or_equal(or_equal(x, u), rest...);
 }