Macro axmac::axr

macro_rules! axr {
    ( $a:ident..$b:ident ) => { ... };
    ( $a:ident..=$b:ident ) => { ... };
    ( $a:ident..$b:expr ) => { ... };
    ( $a:ident..=$b:expr ) => { ... };
    ( ..$a:ident ) => { ... };
    ( ..=$a:ident ) => { ... };
    ( $a:ident.. ) => { ... };
    ( ($a:expr)..$b:ident ) => { ... };
    ( ($a:expr)..=$b:ident ) => { ... };
}

Converts a range of identifiers and/or usize expressions to a range of usize values

Using any identifiers apart from x, y, z or w will result in a compile time error

It is recommended to use parentheses when calling this macro for clarity

Possible Variations

// PLEASE NOTE!
//  x => 0usize
//  y => 1
//  z => 2
//  w => 3

// Range with identifiers
assert_eq!(axr!(x..z), 0..2);

// RangeInclusive with identifiers
assert_eq!(axr!(y..=w), 1..=3);

// RangeTo with identifiers
assert_eq!(axr!(..z), ..2);

// RangeToInclusive with identifiers
assert_eq!(axr!(..=w), ..=3);

// RangeFrom with identifier
assert_eq!(axr!(y..), 1..);

// Range with identifier and expression
assert_eq!(axr!(x..10), 0..10);

// RangeInclusive with identifier and expression
assert_eq!(axr!(x..=7), 0..=7);

// Range with expression and identifier
//  The parentheses around the expression are compulsory
assert_eq!(axr!((0)..z), 0..2);

// RangeInclusive with expression and identifier
//  The parentheses around the expression are compulsory
assert_eq!(axr!((1)..=w), 1..=3);