Activity for 1.2.2 Display - Formatting a Complex Struct

[j-medland]

I am having some difficulty with achieving the activity in 1.2.2 Display due to the presence of a space between the sign and the imaginary component.

The activity asks to add a fmt::Display implementation for a struct representing a complex number with real and imaginary f64 values with the output:

3.3 + 7.2i

Using "{} {:+}i" would seem like the reasonable approach but this yields 3.3 +7.2i and it is not obvious how I can pad between the sign and imaginary component to get the output specified. As the activity doesn't test complex numbers with a negative imaginary component, some folks might just use "{} + {}i" and move on to the next lesson.

So am I missing something - is there a way to add padding? should I use some conditional statement based on the sign of the imaginary component?

I noticed this change was introduced by PR #1123 where previous to this, there was no space.

Cheers