Curriculum Foundations Compiler feedback exercise 2 · mcq-explain

Compiler feedback

Inside the rustc diagnostic below, which line is the ACTIONABLE suggestion you can copy verbatim into your code? error[E0277]: cannot multiply i32 by &str --> src/main.rs:4:9 | 4 | let _ = 7 * "hi"; = note: the trait Mul<&str> is not implemented for i32 help: consider converting the value with .parse::<i32>()

TypeScript reference

The = note: the trait Mul<&str> is not implemented ... line — a related fact, not an action.

The error[E0277]: cannot multiply ... line — that's the error header.

The --> src/main.rs:4:9 line — the file/line/column span.

The help: consider converting the value with .parse::<i32>() line — help: lines hold the suggested fix, often pasteable as-is.

About this theme

Rust is learned with the compiler, not around it. Before ownership starts, learners need the habit of reading error[E...], spans, notes, and help: suggestions. Planned exercises: 1. identify the primary error line. 2. recognise a help: suggestion. 3. choose the fix for a type mismatch. 4. fill a corrected variable name. 5. fill a corrected type. 6. apply a compiler hint to one line. 7. explain why a warning is not an error. 8. fix a short program from a rustc diagnostic. 9. use the diagnostic to repair a function.