Function grid_trait::grid3::alloc_gen

pub fn alloc_gen<I, T, F>(
    x_len: i32, 
    y_len: i32, 
    z_len: i32, 
    generator: F
) -> ArrayGrid3<T> where
    I: From<Vector3<i32>>,
    F: FnMut(I) -> T, 

Allocate a grid on the heap, populate with a function.