
vec_c() fails with complex foreign S3 classes
=============================================

> x <- structure(foobar(1), attr_foo = "foo")
> y <- structure(foobar(2), attr_bar = "bar")
> vec_c(x, y)
Error: Can't combine `..1` <vctrs_foobar> and `..2` <vctrs_foobar>.
x Some attributes are incompatible.
i The author of the class should implement vctrs methods.
i See <https://vctrs.r-lib.org/reference/faq-error-incompatible-attributes.html>.


vec_c() fails with complex foreign S4 classes
=============================================

> joe <- .Counts(c(1L, 2L), name = "Joe")
> jane <- .Counts(3L, name = "Jane")
> vec_c(joe, jane)
Error: Can't combine `..1` <vctrs_Counts> and `..2` <vctrs_Counts>.
x Some attributes are incompatible.
i The author of the class should implement vctrs methods.
i See <https://vctrs.r-lib.org/reference/faq-error-incompatible-attributes.html>.


vec_c() fallback doesn't support `name_spec` or `ptype`
=======================================================

> with_c_foobar(vec_c(foobar(1), foobar(2), .name_spec = "{outer}_{inner}"))
Error: Can't use a name specification with non-vctrs types.
vctrs methods must be implemented for class `vctrs_foobar`.
See <https://vctrs.r-lib.org/articles/s3-vector.html>.

> with_c_foobar(vec_c(foobar(1), foobar(2), .ptype = ""))
Error: Can't convert <vctrs_foobar> to <character>.


can ignore names by providing a `zap()` name-spec (#232)
========================================================

> vec_c(a = c(b = letters), b = 1, .name_spec = zap())
Error: Can't combine `a` <character> and `b` <double>.

