[meta] Add hb_is_base_of

This commit is contained in:
Behdad Esfahbod 2019-05-10 11:26:39 -07:00
parent 98974ac16f
commit 30e4ae6bd1
2 changed files with 23 additions and 0 deletions

View File

@ -147,6 +147,13 @@ struct hb_is_convertible
};
#define hb_is_convertible(From,To) hb_is_convertible<From, To>::value
template <typename Base, typename Derived>
struct hb_is_base_of
{
static constexpr bool value = hb_is_convertible (hb_decay<Derived> *, hb_decay<Base> *);
};
#define hb_is_base_of(Base,Derived) hb_is_base_of<Base, Derived>::value
template <typename From, typename To>
struct hb_is_cr_convertible
{

View File

@ -78,5 +78,21 @@ main (int argc, char **argv)
static_assert (hb_is_convertible (int *, void *), "");
static_assert (!hb_is_convertible (void *, int *), "");
struct Y : X {};
static_assert (hb_is_base_of (void, void));
static_assert (hb_is_base_of (void, int));
static_assert (!hb_is_base_of (int, void));
static_assert (hb_is_base_of (int, int));
static_assert (hb_is_base_of (const int, int));
static_assert (hb_is_base_of (int, const int));
static_assert (hb_is_base_of (X, X));
static_assert (hb_is_base_of (X, Y));
static_assert (hb_is_base_of (const X, Y));
static_assert (hb_is_base_of (X, const Y));
static_assert (!hb_is_base_of (Y, X));
return 0;
}