null_allocator.h

// Copyright 2023 The Pigweed Authors
//
// Licensed under the Apache License, Version 2.0 (the "License"); you may not
// use this file except in compliance with the License. You may obtain a copy of
// the License at
//
//     https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
// License for the specific language governing permissions and limitations under
// the License.
#pragma once
 
#include <cstddef>
 
#include "pw_allocator/allocator.h"
#include "pw_allocator/capability.h"
 
namespace pw::allocator {
 
class NullAllocator : public Allocator {
 public:
  static constexpr Capabilities kCapabilities = 0;
 
  // TODO(b/326509341): Make the constructor private once downstream consumers
  // are migrated.
  friend NullAllocator& GetNullAllocator();
  constexpr NullAllocator() : Allocator(kCapabilities) {}
 
 private:
  void* DoAllocate(Layout) override { return nullptr; }
 
  void DoDeallocate(void*) override {}
 
  void DoDeallocate(void* ptr, Layout) override { DoDeallocate(ptr); }
};
 
NullAllocator& GetNullAllocator();
 
}  // namespace pw::allocator