simple question about UFCS and templates...wasFound(i) works but not i.wasFound()

[WhatMeWorry via Digitalmars-d-learn]

```
   bool wasFound(I)(I result)
    {
        return(result != -1);
    }
    bool existPoint(Point b, int cost)
    {
        auto i = closed.countUntil(b);

        if(wasFound(i))   // -1 is returned if no point b is 
found in the range
```

The above compiles and executes successfully. But the following 
fails with:
app.d(179,13): Error: no property `wasFound` for `i` of type 
`long`

I thought the templated function would take care of any type.
```
    bool wasFound(I)(I result)
    {
        return(result != -1);
    }

    bool existPoint(Point b, int cost)
    {
        auto i = closed.countUntil(b);  // Note: closed

        if(i.wasFound())   // -1 is returned if no point b is 
found in the range
```