add signatures for blocks

src/stan/callbacks/unique_stream_writer.hpp

@@ -127,6 +127,39 @@ class unique_stream_writer final : public writer {
                                  ", ", "", "", "\n", "", "");
     *output_ << values.transpose().format(CommaInitFmt);
   }
+  /**
+   * Writes a set of values in csv format followed by a newline.
+   *
+   * Note: the precision of the output is determined by the settings
+   *  of the stream on construction.
+   *
+   * @param[in] v Values in a block representing an Eigen column vector
+   */
+  virtual void operator()(const Eigen::Block<Eigen::Matrix<double, -1, -1>, -1, 1, true>) {
+    if (output_ == nullptr)
+      return;
+    Eigen::IOFormat CommaInitFmt(Eigen::StreamPrecision, Eigen::DontAlignCols,
+                                 ", ", "", "", "\n", "", "");
+    *output_ << values.transpose().format(CommaInitFmt);
+  }
+
+  /**
+   * Writes a set of values in csv format followed by a newline.
+   *
+   * Note: the precision of the output is determined by the settings
+   *  of the stream on construction.
+   *
+   * @param[in] v Values in a block representing an Eigen row vector
+   */
+  virtual void operator()(const Eigen::Block<Eigen::Matrix<double, -1, -1>, 1, -1, true>) {
+    if (output_ == nullptr)
+      return;
+    Eigen::IOFormat CommaInitFmt(Eigen::StreamPrecision, Eigen::DontAlignCols,
+                                 ", ", "", "", "\n", "", "");
+    *output_ << values.format(CommaInitFmt);
+
+  }
+
 
   /**
    * Writes the comment_prefix to the stream followed by a newline.

src/stan/callbacks/writer.hpp

@@ -77,6 +77,27 @@ class writer {
    * @param[in] v Values in an Eigen row vector
    */
   virtual void operator()(const Eigen::Matrix<double, 1, -1>& values) {}
+
+  /**
+   * Writes a set of values in csv format followed by a newline.
+   *
+   * Note: the precision of the output is determined by the settings
+   *  of the stream on construction.
+   *
+   * @param[in] v Values in a block representing an Eigen column vector
+   */
+  virtual void operator()(const Eigen::Block<Eigen::Matrix<double, -1, -1>, -1, 1, true>) {}
+
+  /**
+   * Writes a set of values in csv format followed by a newline.
+   *
+   * Note: the precision of the output is determined by the settings
+   *  of the stream on construction.
+   *
+   * @param[in] v Values in a block representing an Eigen row vector
+   */
+  virtual void operator()(const Eigen::Block<Eigen::Matrix<double, -1, -1>, 1, -1, true>) {}
+
 };
 
 }  // namespace callbacks