buffer.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 <array>
#include <cstddef>
#include <cstdint>
 
#include "pw_bytes/span.h"
#include "pw_result/result.h"
 
namespace pw::allocator {
 
template <typename T, size_t kBufferSize, size_t kAlignment = 1>
class WithBuffer {
 public:
  static constexpr size_t kCapacity = kBufferSize;
 
  ByteSpan as_bytes() { return buffer_; }
  std::byte* data() { return buffer_.data(); }
  size_t size() const { return buffer_.size(); }
 
  T& operator*() { return obj_; }
  const T& operator*() const { return obj_; }
 
  T* operator->() { return &obj_; }
  const T* operator->() const { return &obj_; }
 
 private:
  alignas(kAlignment) std::array<std::byte, kBufferSize> buffer_;
  T obj_;
};
 
}  // namespace pw::allocator