Syntax for "var" in types
=========================

Options:

    var T           var T           %T          var:T           var&T
    ref T           ref T           ref T       ref T           ref T
    var ref T       var ref T       %ref T      var:ref T       var&ref T
    ref var T       rwref T         ref %T      ref var:T       ref var&T
    var ref var T   var rwref T     %ref %T     var:ref var:T   var&ref var&T

    var+T           var*T           var~T           var-T
    ref T           ref T           ref T           ref T
    var+ref T       var*ref T       var~ref T       var-ref T
    ref var+T       ref var*T       ref var~T       ref var-T
    var+ref var+T   var*ref var*T   var~ref var~T   var-ref var-T

In my opinion, the last one (var-T) is the best one.
It is obvious that var and the type that follows it belong together.
Is is obvious that "var" means variable, unlike %$: etc.
It is kind of obvious what "var-int i" and "var-ref int i" are.
Downsides:
* Not obvious that all types can have "var-" attached.
* Not obvious that "-" is special character.
These problems could be solved by ~, but on the other hand, ~ is harder to
type on most keyboard layouts (far away, or requries Alt Gr key press,
or requires swipe or long-press (on mobile keyboards)).


If using a "type sigill", which character to use?

    !#$%&'*+,-./:;<=>?@[\^_`{|~

    definitiely impossible characters: #",_
    maybe impossible characters: *+-./<=>{}[]()
    confusing characters: &?;^

    !T  $T  %T  &T  'T  *T  +T  -T  .T  /T  :T  ;T  <T  =T  >T
    ?T  @T  [T  \T  ^T  `T  {T  |T  ~T

    combinations:
    (T) <T> [T] {T}

    This leaves us with:
    !$%':@\`|~

    common usages in other languages:

    @T   array, attribute
    $T   variable in PHP (not used on types)
    %T
    &T   reference
    ?T   optional type
    'T   
    ^T   (or T^), pointer/reference
    ~T   destructor, not
    \T   namespace in PHP, escape sequence. used in TeX

    \T
    ref T
    ref \T
    \ref \T