/// Context with all Rust's constants in `f64::consts` available by default.
///
/// Alternatively, specifiy constants with `math_consts_context!(E, PI, TAU, ...)`
/// Available constants can be found in the [`core::f64::consts module`](https://doc.rust-lang.org/nightly/core/f64/consts/index.html).
#[macro_export]
macro_rules! math_consts_context {
    () => {
        $crate::math_consts_context!(
            PI,
            TAU,
            FRAC_PI_2,
            FRAC_PI_3,
            FRAC_PI_4,
            FRAC_PI_6,
            FRAC_PI_8,
            FRAC_1_PI,
            FRAC_2_PI,
            FRAC_2_SQRT_PI,
            SQRT_2,
            FRAC_1_SQRT_2,
            E,
            LOG2_10,
            LOG2_E,
            LOG10_2,
            LOG10_E,
            LN_2,
            LN_10
        )
    };
    ($($name:ident),*) => {{
        $crate::context_map! {
            $(
                stringify!($name) => float core::f64::consts::$name,
            )*
        }
    }};
}

#[cfg(test)]
mod tests {

    #[test]
    fn math_consts_context() {
        let context: crate::HashMapContext = math_consts_context!().unwrap();

        {
            use crate::{Context, Value};

            assert_eq!(
                context.get_value("PI"),
                Some(&Value::Float(core::f64::consts::PI))
            );
        }
    }
}
