message: Add examples for matrices to dim documentation
diff: @@ -70,6 +70,9 @@ struct dim {
  * object, the remaining dimensions are set to the same value as the last
  * value given.
  *
  + * For example, in the context of matrices `dim<2>{2, 3}` creates the
  + * dimensions for a 2-by-3 matrix.
  + *
  * @param first first dimension
  * @param rest other dimensions
  */
  @@ -82,6 +85,10 @@ struct dim {
  /**
  * Returns the requested dimension.
  *
  + * For example, if `d`is a dim<2> object representing matrix dimensions,
  + * `d[0]` returns the number of rows, and `d[1]` returns the number of
  + * columns.
  + *
  * @param dimension the requested dimension
  *
  * @return the `dimension`-th dimension
  @@ -115,7 +122,7 @@ struct dim {
  }
  /**
  - * Checks if two dime objects are equal.
  + * Checks if two dim objects are equal.
  *
  * @param x first object
  * @param y second object
  