Lower/UpperExp inconsistent between integers and floats

[nrabulinski]

I tried this code:

println!("{:.*e}", 0, 25);
println!("{:.*e}", 0, 25.0);

I expected to see this happen:
The output should be the same regardless if I'm formatting an integer or a float, in this case most likely 3e1.

Instead, this happened:

3.e1
2e1

Happens in both latest stable and nightly.

EDIT: I'm suspecting this is actually two separate bugs in both the integer and float implementation - the integer result contains a . which should not be there, and the float gets rounded down to 2 despite 25.1 rounding to 3e1 - which is the result I would expect for 25.0 as well.

[joshtriplett]

For the floating-point portion of this, I think the default is "round to nearest even", which would make 2e1 the correct rounding.

It seems odd that integers and floating-point values have different rounding here.

[nrabulinski]

For the floating-point portion of this, I think the default is "round to nearest even", which would make 2e1 the correct rounding.

It seems odd that integers and floating-point values have different rounding here.

https://play.rust-lang.org/?version=stable&mode=debug&edition=2018&gist=a056ffde1e5a237e2e26351615775809

[fmease]

I can no longer reproduce this on the latest nightly (1.77, 2024-01-22 d5fd099), I get:

2e1
2e1

Interestingly, stable (1.75) produces the following which still contains the rounding error:

3e1
2e1

Closing as completed. Please ping me if I should reopen this issue.