GitFOSS

struct Pointer(T)
  def self.null
    new 0u64
  end

  def null?
    address == 0u64
  end

  def +(other : Int)
    Pointer(T).new(address + other * sizeof(T))
  end

  def -(other : Int)
    Pointer(T).new(address - other * sizeof(T))
  end

  def -(other : self)
    (address - other.address) // sizeof(T)
  end

  def [](offset : Int)
    (self + offset).value
  end

  def []=(offset : Int, value : T)
    (self + offset).value = value
  end

  def ==(other : self)
    address == other.address
  end

  def realloc(new_size : UInt64)
    Pointer(T).new Intrinsics.realloc(address, new_size * sizeof(T))
  end

  def memcpy(dest : Pointer, src : Pointer, size : USize)
    Intrinsics.memcpy dest.address, src.address, size
  end

  def memcmp(a : Pointer, b : Pointer, size : USize)
    Intrinsics.memcmp a.address, b.address, size
  end

  def memset(dest : Pointer, value : UInt8, size : USize)
    Intrinsics.memset dest.address, value, size
  end
  
  def malloc_atomic(size : UInt32)
    ptr = realloc(size)
    if ptr.null?
      ptr = realloc(size)
      raise "Out of memory" if ptr.null?
    else
      ptr = realloc(size)
    end
    ptr
  end

end