R: Default cast and ptype2 methods

vec_default_cast {vctrs} | R Documentation

## Default cast and ptype2 methods

### Description

These functions are automatically called when no `vec_ptype2()` or `vec_cast()` method is implemented for a pair of types.

- They apply special handling if one of the inputs is of type `AsIs` or `sfc`.

- They attempt a number of fallbacks in cases where it would be too inconvenient to be strict:

  - If the class and attributes are the same they are considered compatible. `vec_default_cast()` returns `x` in this case.

  - In case of incompatible data frame classes, they fall back to `data.frame`. If an incompatible subclass of tibble is involved, they fall back to `tbl_df`.

- Otherwise, an error is thrown with `stop_incompatible_type()` or `stop_incompatible_cast()`.

### Usage

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

    vec_default_ptype2(x, y, ..., x_arg = "", y_arg = "")

### Arguments

`x` | Vectors to cast.
`to` | Type to cast to. If `NULL`, `x` will be returned as is.
`...` | For `vec_cast_common()`, vectors to cast. For `vec_cast()`, `vec_cast_default()`, and `vec_restore()`, these dots are only for future extensions and should be empty.
`x_arg` | Argument names for `x` and `to`. These are used in error messages to inform the user about the locations of incompatible types (see `stop_incompatible_type()`).
`to_arg` | Argument names for `x` and `to`. These are used in error messages to inform the user about the locations of incompatible types (see `stop_incompatible_type()`).

[Package vctrs version 0.3.2 Index]