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 //! count_where adds a method to the Iterator trait that allows one to count the numbers of items matching a given predicate, much like a custom function in Swift that filters a sequence and return the count.
 //! # Quick Start
 //! 
 //! The easiest way to get things working, after adding the crate as a dependency would be like this:
 //! 
 //! ```
 //! use count_where::CountWhere;
 //! 
 //! fn main() {
 //!  let numbers = [5, 5, 5, 2, 1];
 //!  let number = 5;
 //!  println!("{} appears {} times.", number, numbers.iter().count_where(|n| **n == number));
 //! }
 //! ```
 //! 
 //! The above goes through a specified array and looks for each instance that the number is 5 and displays that to the user.

mod count_where_ext; // make extension trait visible to library

// give trait extension an easy to remember name
pub use crate::count_where_ext::CountWhereExt as CountWhere;

#[cfg(test)]
mod tests {
    
    use super::*;
    #[test]
    fn has_three_fives() {
        let numbers = [5, 5, 5, 2, 1];

        assert_eq!(3, numbers.iter().count_where(|n| **n == 5))
    }

    #[test]
    fn has_two_numbers_less_than_five() {
        let numbers = [5, 5, 5, 2, 1];

        assert_eq!(2, numbers.iter().count_where(|n| **n < 5))
    }
}