map 1.3.0

This crate provides the `map!` macro and `map_insert!` macro, to create a HashMap collection and insert key-value pairs. Inspired by the `vec!` macro.
Documentation 
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/// Create a new map collection and insert key-value pairs.
///
/// Example with tuple syntax:
///
/// ```
/// # use ::map::*;
/// let m = map!((1, 2), (3, 4));
/// ```
///
/// Example with arrow syntax:
///
/// ```
/// # use ::map::*;
/// let m = map!(1 => 2, 3 => 4);
/// ```
///
/// Example with multiple lines and tuple syntax:
///
/// ```
/// # use ::map::*;
/// let m = map!(
///     (1, 2),
///     (3, 4),
/// );
/// ```
///
/// Example with multiple lines and arrow syntax:
///
/// ```rust
/// # use ::map::*;
/// let m = map!(
///     1 => 2,
///     3 => 4,
/// );
/// ```
///
/// Equivalent Rust standard code:
///
/// ```
/// # use std::collections::HashMap;
/// let mut m = HashMap::new();
/// m.insert(1, 2);
/// m.insert(3, 4);
/// ```
///
#[allow(unused_macros)]
#[macro_export]
macro_rules! map {
    // tuple syntax
    ( $(( $k:expr, $v:expr )),* $(,)?) => {
        {
            let mut m = ::std::collections::HashMap::new();
            $(
                m.insert($k, $v);
            )*
            m
        }
    };
    // arrow syntax
    ( $( $k:expr => $v:expr ),* $(,)?) => {
        {
            let mut m = ::std::collections::HashMap::new();
            $(
                m.insert($k, $v);
            )*
            m
        }
    };
}

#[cfg(test)]
mod test {

    mod tuple_syntax {

        mod one_line {
            use std::collections::HashMap;

            #[test]
            fn trailing_comma() {
                let x = map!((1, 2), (3, 4),);
                assert_eq!(x, HashMap::from([(1, 2), (3, 4)]));
            }

            #[test]
            fn no_trailing_comma() {
                let x = map!((1, 2), (3, 4));
                assert_eq!(x, HashMap::from([(1, 2), (3, 4)]));
            }
        }

        mod multiple_lines {
            use std::collections::HashMap;

            #[test]
            fn trailing_comma() {
                let x = map!(
                    (1, 2),
                    (3, 4),
                );
                assert_eq!(x, HashMap::from([(1, 2), (3, 4)]));
            }

            #[test]
            fn no_trailing_comma() {
                let x = map!(
                    (1, 2),
                    (3, 4)
                );
                assert_eq!(x, HashMap::from([(1, 2), (3, 4)]));
            }
        }
    }

    mod arrow_syntax {

        mod one_line {
            use std::collections::HashMap;

            #[test]
            fn trailing_comma() {
                let x = map!(1 => 2, 3 => 4,);
                assert_eq!(x, HashMap::from([(1, 2), (3, 4)]));
            }

            #[test]
            fn no_trailing_comma() {
                let x = map!(1 => 2, 3 => 4);
                assert_eq!(x, HashMap::from([(1, 2), (3, 4)]));
            }
        }

        mod multiple_lines {
            use std::collections::HashMap;

            #[test]
            fn trailing_comma() {
                let x = map!(
                    1 => 2,
                    3 => 4,
                );
                assert_eq!(x, HashMap::from([(1, 2), (3, 4)]));
            }

            #[test]
            fn no_trailing_comma() {
                let x = map!(
                    1 => 2,
                    3 => 4
                );
                assert_eq!(x, HashMap::from([(1, 2), (3, 4)]));
            }
        }
    }
  
}