This is a function for developers to use when extending vctrs. It casts a list to a more specific vectoring type, keeping the length constant. It does this by discarding (with a warning), any elements after the 1. It is called from vec_cast.XYZ.list() methods to preserve symmetry with vec_cast.list.XYZ().

vec_list_cast(x, to, ..., x_arg = "", to_arg = "")

## Arguments

x A list Type to coerce to These dots are for future extensions and must be empty.

## Details

See vignette("s3-vector") for details.