rust/comprehensive-rust
1
0
Fork 0
mirror of https://github.com/google/comprehensive-rust.git synced 2025-02-16 01:20:08 +02:00
Code Issues Releases Activity

Add safety comment.

Browse Source
This commit is contained in:
Andrew Walbran 2023-01-17 16:35:39 +00:00
parent 47e28e87c0
commit d07171e76d
1 changed files with 4 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
src/unsafe/unsafe-functions.md
View File

@ -1,13 +1,15 @@
# Calling Unsafe Functions # Calling Unsafe Functions
A function or method can be marked `unsafe` if it has extra preconditions you A function or method can be marked `unsafe` if it has extra preconditions you
must uphold: must uphold to avoid undefined behaviour:
```rust,editable ```rust,editable
fn main() { fn main() {
let emojis = "🗻∈🌏"; let emojis = "🗻∈🌏";
// Safe because the indices are in the correct order, within the bounds of
// the string slice, and lie on UTF-8 sequence boundaries.
unsafe { unsafe {
// Undefined behavior if indices do not lie on UTF-8 sequence boundaries.
println!("{}", emojis.get_unchecked(0..4)); println!("{}", emojis.get_unchecked(0..4));
println!("{}", emojis.get_unchecked(4..7)); println!("{}", emojis.get_unchecked(4..7));
println!("{}", emojis.get_unchecked(7..11)); println!("{}", emojis.get_unchecked(7..11));