Matching on box attempt

constant_fold.rs

enum ExprNode {
    Number(f64),
    Variable(CString),
    BinaryOperation(char, Box<ExprNode>, Box<ExprNode>),
    FunctionCall(CString, Vec<Box<ExprNode>>),
    IfElse(Box<ExprNode>, Box<ExprNode>, Box<ExprNode>),
    ForLoop(Box<ExprNode>, Box<ExprNode>, Option<Box<ExprNode>>, Box<ExprNode>),
}

if let (ExprNode::Number(l), ExprNode::Number(r)) = (*lhs, *rhs) {
    let value = match binop {
        '+' => l + r,
        '-' => l - r,
        '*' => l * r,
        '<' => {
            match (l < r) {
                true => 1.0,
                false => 0.0,
            }
        }
        _ => unreachable!("Unimplemented binary operation"),
    };
    lhs = Box::new(ExprNode::Number(value))
} else {
    lhs = Box::new(ExprNode::BinaryOperation(binop, lhs, rhs));
};