# Rust - Lifetimes ## [Common Rust Lifetime Misconceptions](https://github.com/pretzelhammer/rust-blog/blob/master/posts/common-rust-lifetime-misconceptions.md#2-if-t-static-then-t-must-be-valid-for-the-entire-program) - [1) `T` only contains owned types](https://github.com/pretzelhammer/rust-blog/blob/master/posts/common-rust-lifetime-misconceptions.md#1-t-only-contains-owned-types) - [2) if `T: 'static` then `T` must be valid for the entire program](https://github.com/pretzelhammer/rust-blog/blob/master/posts/common-rust-lifetime-misconceptions.md#2-if-t-static-then-t-must-be-valid-for-the-entire-program) - [3) `&'a T` and `T: 'a` are the same thing](https://github.com/pretzelhammer/rust-blog/blob/master/posts/common-rust-lifetime-misconceptions.md#3-a-t-and-t-a-are-the-same-thing) - [4) my code isn't generic and doesn't have lifetimes](https://github.com/pretzelhammer/rust-blog/blob/master/posts/common-rust-lifetime-misconceptions.md#4-my-code-isnt-generic-and-doesnt-have-lifetimes) - [5) if it compiles then my lifetime annotations are correct](https://github.com/pretzelhammer/rust-blog/blob/master/posts/common-rust-lifetime-misconceptions.md#5-if-it-compiles-then-my-lifetime-annotations-are-correct) - [6) boxed trait objects don't have lifetimes](https://github.com/pretzelhammer/rust-blog/blob/master/posts/common-rust-lifetime-misconceptions.md#6-boxed-trait-objects-dont-have-lifetimes) - [7) compiler error messages will tell me how to fix my program](https://github.com/pretzelhammer/rust-blog/blob/master/posts/common-rust-lifetime-misconceptions.md#7-compiler-error-messages-will-tell-me-how-to-fix-my-program) - [8) lifetimes can grow and shrink at run-time](https://github.com/pretzelhammer/rust-blog/blob/master/posts/common-rust-lifetime-misconceptions.md#8-lifetimes-can-grow-and-shrink-at-run-time) - [9) downgrading mut refs to shared refs is safe](https://github.com/pretzelhammer/rust-blog/blob/master/posts/common-rust-lifetime-misconceptions.md#9-downgrading-mut-refs-to-shared-refs-is-safe) - [10) closures follow the same lifetime elision rules as functions](https://github.com/pretzelhammer/rust-blog/blob/master/posts/common-rust-lifetime-misconceptions.md#10-closures-follow-the-same-lifetime-elision-rules-as-functions)