References inside AST nodes

[108anup]

I am new to rust and am trying to parse SMT constraints from a file using the below code. It seems to me that the rust compiler infers that the AST nodes have a reference to Solver. They should ideally only have a reference to the Context.

Is there a work around to convey to the compiler that the ast nodes should not have a reference to Solver. I tried translating the constraints to a different context before returning the assertions, that did not work. Does fixing this require changes to the crate or should I be using the APIs differently.

Code:

fn myfun<'a>(ctx: &'a z3::Context) -> Vec<z3::ast::Bool<'a>>{
    let s = z3::Solver::new(&ctx);
    let smt2 = std::fs::read_to_string("my_constr.smt2").unwrap();
    s.from_string(smt2);
    let assertions = s.get_assertions();
    assertions
}

fn main() {
    let config = z3::Config::new();
    let ctx = z3::Context::new(&config);
    let ret = myfun(&ctx);
}

Error message:

**error[E0515]: cannot return value referencing local variable `s`
  --> src/scratch.rs:45:5
   |
44 |     let assertions = s.get_assertions();
   |                      - `s` is borrowed here
45 |     assertions
   |     ^^^^^^^^^^ returns a value referencing data owned by the current function
**

[waywardmonkeys]

This is a bug in the crate. I have a local fix.

Is it a problem for you to use the crate via git instead of the last release?

[waywardmonkeys]

Fix is pushed! Hope this helps.

[108anup]

Thanks for the prompt response and fix!!