Function is_range_full 

pub fn is_range_full(
    cx: &LateContext<'_>,
    expr: &Expr<'_>,
    container_path: Option<&Path<'_>>,
) -> bool

Checks whether the given Expr is a range equivalent to a RangeFull.

For the lower bound, this means that:

• either there is none
• or it is the smallest value that can be represented by the range’s integer type

For the upper bound, this means that:

• either there is none
• or it is the largest value that can be represented by the range’s integer type and is inclusive
• or it is a call to some container’s len method and is exclusive, and the range is passed to a method call on that same container (e.g. v.drain(..v.len()))

If the given Expr is not some kind of range, the function returns false.