rust - DuplexStream across tasks and closures -

i'm having trouble lifetimes , borrowed points. i've read manual , borrowed pointer tutorial, but... i'm still stuck.

sketch of main.rs

fn main() {   let (db_child, repo_child):(duplexstream<~str, ~str>, duplexstream<~str, ~str>) = duplexstream();     spawn {         slurp_repos(&repo_child);     } } 

sketch of repos.rs

fn slurp_repos(chan: &'static duplexstream<~str, ~str>) {     ...     request.begin |event| {         ...         chan.send(api_url);     } } 

when compile these modules, main.rs has following error:

main.rs:21:20: 21:31 error: borrowed value not live long enough main.rs:21         slurp_repos(&repo_child);                                ^~~~~~~~~~~ note: borrowed pointer must valid static lifetime... main.rs:13:10: 1:0 note: ...but borrowed value valid block @ 13:10 error: aborting due previous error 

i can't quite figure out how declare duplexstreams lifetime static. or perhaps wrong way go in function type slurp_repos.

if want see full context:

• main.rs
• repos.rs

i'm unable test, guess solution move repo_child stream slurp_repos, is:

fn main() {   let (db_child, repo_child) = duplexstream();     spawn {         slurp_repos(repo_child);     } }  fn slurp_repos(chan: duplexstream<~str, ~str>) {     ...     request.begin |event| {         ...         chan.send(api_url);     } } 

by moving whole endpoint, allows transferred across tasks (because duplexstream sendable). also, note sharing (what use of references allows) endpoint of basic bidirectional stream (which duplexstream is) doesn't make sense: there can 1 person @ each end of telephone.

the error message repo_child not living long enough because type of slurp_repos requires 'static i.e. lasts whole lifetime of program, repo_child doesn't: local function.

the reason compiler tells put 'static on slurp_repos, because sendable reference 1 lifetime. restriction required because have owning task finish before borrowing task does, , destroy/deallocate reference, leaving dangling pointer; in diagrams:

start program/call main   |   v allocate repo_child   |   v spawn -----------------> slurp_repos(chan = &repo_child)   |                          |   v                          v finish                   things chan reference repo_child   |                          |   v                          v deallocate repo_child    general work ...                              |                              v                          more things chan:                             oops, freed; use-after-free bug