From 37419b9a579fbcb1633caa9295a39da405e93904 Mon Sep 17 00:00:00 2001
From: MerryMage <MerryMage@users.noreply.github.com>
Date: Mon, 30 Oct 2017 18:10:05 +0000
Subject: [PATCH] Config/Layer: Allow all keys of a section to be iterated over

---
 Source/Core/Common/Config/Layer.cpp | 12 ++++++++++++
 Source/Core/Common/Config/Layer.h   | 27 +++++++++++++++++++++++++++
 2 files changed, 39 insertions(+)

diff --git a/Source/Core/Common/Config/Layer.cpp b/Source/Core/Common/Config/Layer.cpp
index d4f9e7c633..5a5c4b5f59 100644
--- a/Source/Core/Common/Config/Layer.cpp
+++ b/Source/Core/Common/Config/Layer.cpp
@@ -98,6 +98,18 @@ void Layer::DeleteAllKeys()
   }
 }
 
+Section Layer::GetSection(System system, const std::string& section)
+{
+  return Section{m_map.lower_bound(ConfigLocation{system, section, ""}),
+                 m_map.lower_bound(ConfigLocation{system, section + '\001', ""})};
+}
+
+ConstSection Layer::GetSection(System system, const std::string& section) const
+{
+  return ConstSection{m_map.lower_bound(ConfigLocation{system, section, ""}),
+                      m_map.lower_bound(ConfigLocation{system, section + '\001', ""})};
+}
+
 void Layer::Load()
 {
   if (m_loader)
diff --git a/Source/Core/Common/Config/Layer.h b/Source/Core/Common/Config/Layer.h
index eb2a6bafca..8e56ae308a 100644
--- a/Source/Core/Common/Config/Layer.h
+++ b/Source/Core/Common/Config/Layer.h
@@ -62,6 +62,30 @@ private:
   const LayerType m_layer;
 };
 
+class Section
+{
+public:
+  using iterator = LayerMap::iterator;
+  Section(iterator begin_, iterator end_) : m_begin(begin_), m_end(end_) {}
+  iterator begin() const { return m_begin; }
+  iterator end() const { return m_end; }
+private:
+  iterator m_begin;
+  iterator m_end;
+};
+
+class ConstSection
+{
+public:
+  using iterator = LayerMap::const_iterator;
+  ConstSection(iterator begin_, iterator end_) : m_begin(begin_), m_end(end_) {}
+  iterator begin() const { return m_begin; }
+  iterator end() const { return m_end; }
+private:
+  iterator m_begin;
+  iterator m_end;
+};
+
 class Layer
 {
 public:
@@ -106,6 +130,9 @@ public:
     current_value = new_value;
   }
 
+  Section GetSection(System system, const std::string& section);
+  ConstSection GetSection(System system, const std::string& section) const;
+
   // Explicit load and save of layers
   void Load();
   void Save();