message: works and passes tests, but not test yet for complex matrices.
diff: @@ -19,8 +19,10 @@ impl<T : Display> MatrixMarketDisplay for T
  Displayable(self)
  }
  }
  -/*
  -impl<T : Display> Display for Displayable<T>
  +
  +macro_rules! default_matrixmarket_display_impl {
  + ($t: ty) => {
  + impl Display for Displayable<$t>
  {
  fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
  match self {
  @@ -29,21 +31,21 @@ impl<T : Display> Display for Displayable<T>
  }
  }
  }
  -*/
  -
  -// string conversions
  -impl Display for Displayable<Complex<f64>>
  + impl Display for Displayable<& $t>
  {
  fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
  match self {
  Displayable(it) =>
  - write!(f, "{} {}", it.re, it.im)
  + write!(f, "{}", it)
  }
  }
  }
  + };
  +}
  -// string conversions
  -impl Display for Displayable<Complex<f32>>
  +macro_rules! complex_matrixmarket_display_impl {
  + ($t: ty) => {
  + impl Display for Displayable<Complex<$t>>
  {
  fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
  match self {
  @@ -52,47 +54,22 @@ impl Display for Displayable<Complex<f32>>
  }
  }
  }
  -
  -// string conversions
  -impl Display for Displayable<f64>
  + impl Display for Displayable<&Complex<$t>>
  {
  fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
  match self {
  Displayable(it) =>
  - write!(f, "{}", it)
  - }
  - }
  + write!(f, "{} {}", it.re, it.im)
  }
  -
  -// string conversions
  -impl Display for Displayable<f32>
  -{
  - fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
  - match self {
  - Displayable(it) =>
  - write!(f, "{}", it)
  }
  }
  + };
  }
  -// string conversions
  -impl Display for Displayable<i64>
  -{
  - fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
  - match self {
  - Displayable(it) =>
  - write!(f, "{}", it)
  - }
  - }
  -}
  +default_matrixmarket_display_impl!(i32);
  +default_matrixmarket_display_impl!(f32);
  +default_matrixmarket_display_impl!(i64);
  +default_matrixmarket_display_impl!(f64);
  -// string conversions
  -impl Display for Displayable<i32>
  -{
  - fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
  - match self {
  - Displayable(it) =>
  - write!(f, "{}", it)
  - }
  - }
  -}
  +complex_matrixmarket_display_impl!(f64);
  +complex_matrixmarket_display_impl!(f32);
  