original.name="FunctionRef_Valid_13"
whiley.execute.ignore=true
js.execute.ignore=true
======
>>> main.whiley
type Sized is { int value }
type SizeGetter is function(Sized) ->(int)
type SizeSetter is function(Sized,int) ->(Sized)

function f((SizeSetter|SizeGetter) x) -> int:
    if x is SizeGetter:
        return 1
    else:
        return 0

function getSize(Sized _this) -> int:
    return _this.value

function setSize(Sized _this, int value) -> Sized:
    return { value: value }

public export method test():    
    assume f(&getSize) == 1
    assume f(&setSize) == 0

---