Convert items in Vec that match an if-condition to NaN

Question

I have a Vec<f32> with zero values that I'd like to convert into NaN. Is there a way to do this by modifying the Vec in-place with a conditional statement?

This is what I tried so far:

let mut vector: Vec<f32> = vec![2.0, 0.0, 1.0, 3.0, -1.0, 5.0];
vector
    .iter_mut()
    .for_each(|v| if *v == 0.0 { f32::NAN } else { *v });
println!("{vector:?}");

But the compiler is giving me this error:

error[E0308]: mismatched types
 --> src/io/mod.rs:8:38
  |
8 |         .for_each(|v| if *v == 0.0 { f32::NAN } else { *v });
  |                       ---------------^^^^^^^^--------------
  |                       |              |
  |                       |              expected `()`, found `f32`
  |                       expected this to be `()`

error[E0308]: mismatched types
 --> src/io/mod.rs:8:56
  |
8 |         .for_each(|v| if *v == 0.0 { f32::NAN } else { *v });
  |                       ---------------------------------^^--
  |                       |                                |
  |                       |                                expected `()`, found `f32`
  |                       expected this to be `()`

For more information about this error, try `rustc --explain E0308`.

Can someone point out what the proper syntax should be to get a Vec with 0 replaced with NaN?

Answer 1

You didn’t do any writing:

.for_each(|v| if *v == 0.0 { *v = f32::NAN; });

More typically:

let mut vector: Vec<f32> = vec![2.0, 0.0, 1.0, 3.0, -1.0, 5.0];
for v in &mut vector {
    if *v == 0.0 {
        *v = f32::NAN;
    }
}
println!("{vector:?}");