1 files changed, 111 insertions, 0 deletions
diff --git a/source/blender/blenlib/BLI_generic_value_map.hh b/source/blender/blenlib/BLI_generic_value_map.hh
new file mode 100644
index 00000000000..bd8408526b8
--- /dev/null
+++ b/source/blender/blenlib/BLI_generic_value_map.hh
@@ -0,0 +1,111 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#pragma once
+
+#include "BLI_generic_pointer.hh"
+#include "BLI_linear_allocator.hh"
+#include "BLI_map.hh"
+
+namespace blender {
+
+/**
+ * This is a map that stores key-value-pairs. What makes it special is that the type of values does
+ * not have to be known at compile time. There just has to be a corresponding CPPType.
+ */
+template<typename Key> class GValueMap {
+ private:
+  /* Used to allocate values owned by this container. */
+  LinearAllocator<> &allocator_;
+  Map<Key, GMutablePointer> values_;
+
+ public:
+  GValueMap(LinearAllocator<> &allocator) : allocator_(allocator)
+  {
+  }
+
+  ~GValueMap()
+  {
+    /* Destruct all values that are still in the map. */
+    for (GMutablePointer value : values_.values()) {
+      value.destruct();
+    }
+  }
+
+  /* Add a value to the container. The container becomes responsible for destructing the value that
+   * is passed in. The caller remains responsible for freeing the value after it has been
+   * destructed. */
+  template<typename ForwardKey> void add_new_direct(ForwardKey &&key, GMutablePointer value)
+  {
+    values_.add_new_as(std::forward<ForwardKey>(key), value);
+  }
+
+  /* Add a value to the container that is move constructed from the given value. The caller remains
+   * responsible for destructing and freeing the given value. */
+  template<typename ForwardKey> void add_new_by_move(ForwardKey &&key, GMutablePointer value)
+  {
+    const CPPType &type = *value.type();
+    void *buffer = allocator_.allocate(type.size(), type.alignment());
+    type.move_construct(value.get(), buffer);
+    values_.add_new_as(std::forward<ForwardKey>(key), GMutablePointer{type, buffer});
+  }
+
+  /* Add a value to the container that is copy constructed from the given value. The caller remains
+   * responsible for destructing and freeing the given value. */
+  template<typename ForwardKey> void add_new_by_copy(ForwardKey &&key, GPointer value)
+  {
+    const CPPType &type = *value.type();
+    void *buffer = allocator_.allocate(type.size(), type.alignment());
+    type.copy_construct(value.get(), buffer);
+    values_.add_new_as(std::forward<ForwardKey>(key), GMutablePointer{type, buffer});
+  }
+
+  /* Add a value to the container. */
+  template<typename ForwardKey, typename T> void add_new(ForwardKey &&key, T &&value)
+  {
+    if constexpr (std::is_rvalue_reference_v<T>) {
+      this->add_new_by_move(std::forward<ForwardKey>(key), &value);
+    }
+    else {
+      this->add_new_by_copy(std::forward<ForwardKey>(key), &value);
+    }
+  }
+
+  /* Remove the value for the given name from the container and remove it. The caller is
+   * responsible for freeing it. The lifetime of the referenced memory might be bound to lifetime
+   * of the container. */
+  template<typename ForwardKey> GMutablePointer extract(const ForwardKey &key)
+  {
+    return values_.pop_as(key);
+  }
+
+  template<typename ForwardKey> GPointer lookup(const ForwardKey &key) const
+  {
+    return values_.lookup_as(key);
+  }
+
+  /* Remove the value for the given name from the container and remove it. */
+  template<typename T, typename ForwardKey> T extract(const ForwardKey &key)
+  {
+    GMutablePointer value = values_.pop_as(key);
+    const CPPType &type = *value.type();
+    BLI_assert(type.is<T>());
+    T return_value;
+    type.relocate_assign(value.get(), &return_value);
+    return return_value;
+  }
+
+  template<typename T, typename ForwardKey> const T &lookup(const ForwardKey &key) const
+  {
+    GMutablePointer value = values_.lookup_as(key);
+    BLI_assert(value.is_type<T>());
+    BLI_assert(value.get() != nullptr);
+    return *(const T *)value.get();
+  }
+
+  template<typename ForwardKey> bool contains(const ForwardKey &key) const
+  {
+    return values_.contains_as(key);
+  }
+};
+
+}  // namespace blender