russcip 0.2.3

Rust interface for SCIP
Documentation 
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use crate::ffi;

/// A node in the branch-and-bound tree.
pub struct Node {
    pub(crate) raw: *mut ffi::SCIP_NODE,
}

impl Node {
    #[cfg(feature = "raw")]
    /// Returns a raw pointer to the underlying `ffi::SCIP_NODE` struct.
    pub fn inner(&self) -> *mut ffi::SCIP_NODE {
        self.raw
    }

    /// Returns the number of the node.
    pub fn number(&self) -> usize {
        unsafe { ffi::SCIPnodeGetNumber(self.raw) as usize }
    }

    /// Returns the depth of the node in the branch-and-bound tree.
    pub fn depth(&self) -> usize {
        unsafe { ffi::SCIPnodeGetDepth(self.raw) as usize }
    }

    /// Returns the lower bound of the node.
    pub fn lower_bound(&self) -> f64 {
        unsafe { ffi::SCIPnodeGetLowerbound(self.raw) }
    }
}

#[cfg(test)]
mod tests {
    use crate::{
        branchrule::{BranchRule, BranchingResult},
        model::{Model, ProblemCreated},
    };

    struct NodeDataBranchRule {
        model: Model<ProblemCreated>,
    }

    impl BranchRule for NodeDataBranchRule {
        fn execute(
            &mut self,
            _candidates: Vec<crate::branchrule::BranchingCandidate>,
        ) -> BranchingResult {
            let node = self.model.get_focus_node();
            assert_eq!(node.number(), 1);
            assert_eq!(node.depth(), 0);
            assert!(node.lower_bound() < 6777.0);
            BranchingResult::DidNotRun
        }
    }

    #[test]
    fn node_after_solving() {
        let model = Model::new()
            .hide_output()
            .set_longint_param("limits/nodes", 1)
            .unwrap() // only call brancher once
            .include_default_plugins()
            .read_prob("data/test/gen-ip054.mps")
            .unwrap();

        let br = NodeDataBranchRule {
            model: model.clone_for_plugins(),
        };

        model
            .include_branch_rule("", "", 100000, 1000, 1., Box::new(br))
            .solve();
    }
}