/// <summary>コンストラクタ。</summary>
 /// <param name="buffer">バッファ。</param>
 /// <param name="start">開始位置。</param>
 public TomlIter(TomlInnerBuffer buffer, int start)
 {
     this.buffer = buffer;
     this.point  = start;
 }
 /// <summary>コンストラクタ。</summary>
 /// <param name="buffer">バッファ。</param>
 /// <param name="sr">読み込みストリーム。</param>
 public TomlIter(TomlInnerBuffer buffer, Stream sr)
 {
     this.buffer = buffer;
     this.sr     = sr;
     this.point  = 0;
 }