From 4af8f8e3c8d25a82ccdcf806b0b02fb4273214c8 Mon Sep 17 00:00:00 2001
From: Nicolas Mellado <nmellado0@gmail.com>
Date: Mon, 19 Jul 2021 12:59:34 +0200
Subject: [PATCH] [core] Expose LayerKeyHash struct

Allow to reuse layers hash function outside of MultiIndexedGeometry
---
 src/Core/Geometry/IndexedGeometry.cpp |  2 +-
 src/Core/Geometry/IndexedGeometry.hpp | 10 +++++++---
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/src/Core/Geometry/IndexedGeometry.cpp b/src/Core/Geometry/IndexedGeometry.cpp
index 4eb367fa8fd..2a9868c8071 100644
--- a/src/Core/Geometry/IndexedGeometry.cpp
+++ b/src/Core/Geometry/IndexedGeometry.cpp
@@ -252,7 +252,7 @@ void MultiIndexedGeometry::deepClear() {
 //////////////////////////////////////////////////////////////////////
 //////////////////////////////////////////////////////////////////////
 
-std::size_t MultiIndexedGeometry::KeyHash::operator()( const LayerKeyType& k ) const {
+std::size_t MultiIndexedGeometry::LayerKeyHash::operator()( const LayerKeyType& k ) const {
     // Mix semantic collection into a single identifier string
     std::ostringstream stream;
     std::copy( k.first.begin(), k.first.end(), std::ostream_iterator<std::string>( stream, "" ) );
diff --git a/src/Core/Geometry/IndexedGeometry.hpp b/src/Core/Geometry/IndexedGeometry.hpp
index fccf0c8cef3..6cda1aea48f 100644
--- a/src/Core/Geometry/IndexedGeometry.hpp
+++ b/src/Core/Geometry/IndexedGeometry.hpp
@@ -373,17 +373,21 @@ class RA_CORE_API MultiIndexedGeometry : public AttribArrayGeometry, public Util
 
     /// Note: we cannot store unique_ptr here has unordered_map needs its
     /// elements to be copy-constructible
-    using EntryType = std::pair<bool, GeometryIndexLayerBase*>;
-    struct RA_CORE_API KeyHash {
+    using LayerEntryType = std::pair<bool, GeometryIndexLayerBase*>;
+
+  public:
+    /// Hash function for layer keys
+    struct RA_CORE_API LayerKeyHash {
         std::size_t operator()( const LayerKeyType& k ) const;
     };
 
+  private:
     /// Collection of pairs <lockStatus, Indices>
     /// \note There is no natural ordering for these elements, thus
     /// we need an unordered_map. In contrast to map, transparent hashing
     /// require c++20, so we need to implement them explicitely here
     /// https://en.cppreference.com/w/cpp/container/unordered_map/find
-    std::unordered_map<LayerKeyType, EntryType, KeyHash> m_indices;
+    std::unordered_map<LayerKeyType, LayerEntryType, LayerKeyHash> m_indices;
 };
 
 struct RA_CORE_API PointCloudIndexLayer : public GeometryIndexLayer<Vector1ui> {