Function withFront
Takes a unary function that is called on front of range if it is there
auto auto withFront(alias fun, Range)
(
Range range
)
if (from .std .range .isInputRange!Range);
Since
- 0.0.1
Example
import ddash .utils .optional: some, none;
assert((int[]) .init .withFront!(a => a * a) == none);
assert([3, 2] .withFront!(a => a * a) == some(9));
assert([3, 2] .withFront!"a + 1" == some(4));