def make99(x:{Int})
    x[1] = 99

x := 5
y := {x}
make99(y)
x = y[1]
say "$x $y"
fail unless x == 99
say "$(typeof y)"
fail "Type is: '$(typeof y)'" unless "$(typeof y)" == "{Int}"

def foo(x:{str:String,int:Int}):String
    return x.str

say "Anonymous struct: $({.foo="hi"})"
s := foo({.str="Ret",.int=5})
fail "ret = $s" unless s == "Ret"