Lifetime annotation
In Rust, a lifetime annotation is syntax that names or relates the validity lifetimes of references in types and function signatures.
Refactoring to Rust
A lifetime annotation is Rust syntax that names or relates the validity periods of references in types and function signatures.
- How it is used
- Clarifies which input a returned reference borrows from, including a string slice read from an NGINX request.
- How deep it goes
- Works through inferred and explicit signature relationships and borrow-checker errors, then applies them to an unsafe FFI helper.
- Examples
- Uses a vector-element helper, a rejected vector mutation, and an NGINX request-body conversion.
- What you can do after
- Apply it via Rust function signatures to relate a returned reference to the input whose memory it views.
Learn Rust in a Month of Lunches
A lifetime annotation is Rust syntax that names relationships among the lifetimes of references and values in a type or function signature.
- How it is used
- Uses annotations to express reference validity in function signatures and data types when inference needs help.
- How deep it goes
- Explains reference validity, function and struct syntax, compiler errors, and 'static, but defers broader lifetime forms.
- Examples
- Uses invalid function returns, compiler diagnostics, string literals, and a City struct borrowing from a vector.
- What you can do after
- Diagnose missing lifetime errors and choose between owned data, &'static str, or a named lifetime parameter.
Read how Learn Rust in a Month of Lunches explains lifetime annotation →
Related concepts
- Rcaddressed by · Rc is Rust’s single-threaded reference-counted smart pointer for shared ownership of a value.
- compilerused by · A compiler is software that translates source code into executable code or another representation, while analyzing it according to the source language’s rules.
- lifetimeconfigures · A lifetime is the interval during which a program entity exists and remains valid or accessible under the applicable language rules.
- static lifetimecontrasts with · In Rust, the static lifetime is a lifetime that extends for the entire duration of the program.
- genericscontrasts with · Generics are programming-language constructs that parameterize or generalize types and operations so they can apply to multiple concrete types or input forms.
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