fasteval 0.2.4

// usage:  cargo run --release --example ns_btreemap_str

use std::collections::BTreeMap;
fn main() -> Result<(), fasteval::Error> {
    let mut map : BTreeMap<&'static str,f64> = BTreeMap::new();
    map.insert("x", 2.0);

    let val = fasteval::ez_eval("x * (x + 1)", &mut map)?;
    assert_eq!(val, 6.0);

    Ok(())
}