rust vs c

rustvc.c

// An example of how tuples and treating if statements as expressions makes things nicer

// C version, a snippet from simlpex noise. 

  int i1, j1, k1; // Offsets for second corner of simplex in (i,j,k) coords
  int i2, j2, k2; // Offsets for third corner of simplex in (i,j,k) coords
	if (x0 >= y0) {
		if (y0 >= z0) {
			i1 = 1; j1 = 0; k1 = 0; i2 = 1; j2 = 1; k2 = 0;
		} 
		else if (x0 >= z0) { 
			i1 = 1; j1 = 0; k1 = 0; i2 = 1; j2 = 0; k2 = 1; 
		} 
		else { 
			i1 = 0; j1 = 0; k1 = 1; i2 = 1; j2 = 0; k2 = 1; 
		} 
	}
	else { 
		if (y0<z0) { 
			i1 = 0; j1 = 0; k1 = 1; i2 = 0; j2 = 1; k2 = 1; 
		} 
		else if (x0<z0) { 
			i1 = 0; j1 = 1; k1 = 0; i2 = 0; j2 = 1; k2 = 1; 
		} 
		else { 
			i1 = 0; j1 = 1; k1 = 0; i2 = 1; j2 = 1; k2 = 0; 
		} 
}

// Rust version, less code, variables never exist in unitialized state.
let (i1, j1, k1, i2, j2, k2) = 
  if x0 >= y0 {
      if y0 >= z0 {
              (1, 0, 0, 1, 1, 0)
          } else if x0 >= z0 {
              (1, 0, 0, 1, 0, 1)
          } else {
              (0, 0, 1, 1, 0, 1)
          }
  } else {
          if y0 < z0 {
              (0, 0, 1, 0, 1, 1)
          } else if x0 < z0 {
              (0, 1, 0, 0, 1, 1)
          } else {
              (0, 1, 0, 1, 1, 0)
          }
      };