From 2e2782448c13eccd0a3c71971df7f3cf9f10b998 Mon Sep 17 00:00:00 2001
From: asuessenbach <asuessenbach@nvidia.com>
Date: Wed, 20 Jan 2021 10:33:33 +0100
Subject: [PATCH] Introduce new function StructureChain::isLinked<>()

---
 VulkanHppGenerator.cpp                  | 27 +++++++++++++++++++++++--
 tests/StructureChain/StructureChain.cpp |  6 ++++++
 vulkan/vulkan.hpp                       | 26 ++++++++++++++++++++++--
 3 files changed, 55 insertions(+), 4 deletions(-)

diff --git a/VulkanHppGenerator.cpp b/VulkanHppGenerator.cpp
index 96ac776..548b680 100644
--- a/VulkanHppGenerator.cpp
+++ b/VulkanHppGenerator.cpp
@@ -10665,6 +10665,28 @@ int main( int argc, char ** argv )
       return std::tie( get<T0>(), get<T1>(), get<Ts>()... );
     }
 
+    template <typename ClassType, size_t Which = 0>
+    typename std::enable_if<
+      std::is_same<ClassType, typename std::tuple_element<0, std::tuple<ChainElements...>>::type>::value &&
+        ( Which == 0 ),
+      bool>::type
+      isLinked() const VULKAN_HPP_NOEXCEPT
+    {
+      return true;
+    }
+
+    template <typename ClassType, size_t Which = 0>
+    typename std::enable_if<
+      !std::is_same<ClassType, typename std::tuple_element<0, std::tuple<ChainElements...>>::type>::value ||
+        ( Which != 0 ),
+      bool>::type
+      isLinked() const VULKAN_HPP_NOEXCEPT
+    {
+      static_assert( IsPartOfStructureChain<ClassType, ChainElements...>::valid,
+                     "Can't unlink Structure that's not part of this StructureChain!" );
+      return isLinked( reinterpret_cast<VkBaseInStructure const *>( &get<ClassType, Which>() ) );
+    }
+
     template <typename ClassType, size_t Which = 0>
     void relink() VULKAN_HPP_NOEXCEPT
     {
@@ -10725,9 +10747,10 @@ int main( int argc, char ** argv )
                              Types...> : std::integral_constant<int, Index>
     {};
 
-    bool isLinked( VkBaseInStructure const * pNext )
+    bool isLinked( VkBaseInStructure const * pNext ) const VULKAN_HPP_NOEXCEPT
     {
-      VkBaseInStructure const * elementPtr = reinterpret_cast<VkBaseInStructure const*>(&std::get<0>( static_cast<std::tuple<ChainElements...>&>( *this ) ) );
+      VkBaseInStructure const * elementPtr = reinterpret_cast<VkBaseInStructure const *>(
+        &std::get<0>( static_cast<std::tuple<ChainElements...> const &>( *this ) ) );
       while ( elementPtr )
       {
         if ( elementPtr->pNext == pNext )
diff --git a/tests/StructureChain/StructureChain.cpp b/tests/StructureChain/StructureChain.cpp
index e417122..f541f23 100644
--- a/tests/StructureChain/StructureChain.cpp
+++ b/tests/StructureChain/StructureChain.cpp
@@ -74,6 +74,10 @@ int main( int /*argc*/, char ** /*argv*/ )
                        vk::PhysicalDevicePushDescriptorPropertiesKHR>
       sc7;
 
+    // some checks on unmodified chains
+    assert( sc7.isLinked<vk::PhysicalDeviceProperties2>() );
+    assert( sc7.isLinked<vk::PhysicalDeviceMaintenance3Properties>() );
+
     // some invalid StructureChains
     // clang-format off
     //vk::StructureChain<vk::PhysicalDeviceIDProperties, vk::PhysicalDeviceMaintenance3Properties> x;
@@ -91,6 +95,7 @@ int main( int /*argc*/, char ** /*argv*/ )
 
     // unlink a struct from a StructureChain
     sc7.unlink<vk::PhysicalDeviceMaintenance3Properties>();
+    assert( !sc7.isLinked<vk::PhysicalDeviceMaintenance3Properties>() );
 
     // some invalid unlink calls
     // clang-format off
@@ -102,6 +107,7 @@ int main( int /*argc*/, char ** /*argv*/ )
 
     // re-link a struct
     sc7.relink<vk::PhysicalDeviceMaintenance3Properties>();
+    assert( sc7.isLinked<vk::PhysicalDeviceMaintenance3Properties>() );
 
     // invalid re-linking
     // clang-format off
diff --git a/vulkan/vulkan.hpp b/vulkan/vulkan.hpp
index 579c0b9..adff991 100644
--- a/vulkan/vulkan.hpp
+++ b/vulkan/vulkan.hpp
@@ -1043,6 +1043,28 @@ namespace VULKAN_HPP_NAMESPACE
       return std::tie( get<T0>(), get<T1>(), get<Ts>()... );
     }
 
+    template <typename ClassType, size_t Which = 0>
+    typename std::enable_if<
+      std::is_same<ClassType, typename std::tuple_element<0, std::tuple<ChainElements...>>::type>::value &&
+        ( Which == 0 ),
+      bool>::type
+      isLinked() const VULKAN_HPP_NOEXCEPT
+    {
+      return true;
+    }
+
+    template <typename ClassType, size_t Which = 0>
+    typename std::enable_if<
+      !std::is_same<ClassType, typename std::tuple_element<0, std::tuple<ChainElements...>>::type>::value ||
+        ( Which != 0 ),
+      bool>::type
+      isLinked() const VULKAN_HPP_NOEXCEPT
+    {
+      static_assert( IsPartOfStructureChain<ClassType, ChainElements...>::valid,
+                     "Can't unlink Structure that's not part of this StructureChain!" );
+      return isLinked( reinterpret_cast<VkBaseInStructure const *>( &get<ClassType, Which>() ) );
+    }
+
     template <typename ClassType, size_t Which = 0>
     void relink() VULKAN_HPP_NOEXCEPT
     {
@@ -1106,10 +1128,10 @@ namespace VULKAN_HPP_NAMESPACE
                              Types...> : std::integral_constant<int, Index>
     {};
 
-    bool isLinked( VkBaseInStructure const * pNext )
+    bool isLinked( VkBaseInStructure const * pNext ) const VULKAN_HPP_NOEXCEPT
     {
       VkBaseInStructure const * elementPtr = reinterpret_cast<VkBaseInStructure const *>(
-        &std::get<0>( static_cast<std::tuple<ChainElements...> &>( *this ) ) );
+        &std::get<0>( static_cast<std::tuple<ChainElements...> const &>( *this ) ) );
       while ( elementPtr )
       {
         if ( elementPtr->pNext == pNext )