Still struggling to convert C++ code

Yeah, the spelling gets me. I've added doc aliases:


got my first encode to generate a correct PNG file but cargo gave me warnings..Can I ignore them ?

D6204 ~/PNG $cargo run
Compiling PNG v0.1.0 (/home/D6204/PNG)
warning: crate PNG should have a snake case name
= note: #[warn(non_snake_case)] on by default
= help: convert the identifier to snake case: png

warning: unused std::result::Result that must be used
--> src/
17 | encode32_file("out.png", &img, W, H) ;
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
= note: #[warn(unused_must_use)] on by default
= note: this Result may be an Err variant, which should be handled

Finished dev [unoptimized + debuginfo] target(s) in 0.58s
 Running `target/debug/PNG`

out.png !
D6204 ~/PNG $

Well, they're not errors, so you can ignore them. Generally better to correct them though...

The first is about naming conventions.

The second means that encode32_file() could fail, and you should probably handle that case instead of ignoring the failure (even if "handling it" means explicitily ignoring it in your code). Ignoring these is a bug often enough that it's common to forbid the warning.

Side note: You can put your compiler output into```text blocks to make it easier to read.

1 Like

You're expected to handle errors, e.g.

if let Err(e) = encode32_file(…) {
    eprintln!("oops! {}", e);

See ? (try) operator to remove boilerplate.

Rust also has its style/naming conventions that it will nudge you towards. See also cargo clippy.

Thanks ! I'm just starting to get into Rust`s way of handling errors .. Some of my C++ habits are leading me to do some bad Rust coding..

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