Struct core::ptr::DynMetadata [−][src]
pub struct DynMetadata<Dyn: ?Sized> { /* fields omitted */ }Expand description
The metadata for a Dyn = dyn SomeTrait trait object type.
It is a pointer to a vtable (virtual call table) that represents all the necessary information to manipulate the concrete type stored inside a trait object. The vtable notably it contains:
- type size
- type alignment
- a pointer to the type’s
drop_in_placeimpl (may be a no-op for plain-old-data) - pointers to all the methods for the type’s implementation of the trait
Note that the first three are special because they’re necessary to allocate, drop, and deallocate any trait object.
It is possible to name this struct with a type parameter that is not a dyn trait object
(for example DynMetadata<u64>) but not to obtain a meaningful value of that struct.
Implementations
Returns the size of the type associated with this vtable.
Returns the alignment of the type associated with this vtable.
Trait Implementations
This method returns an ordering between self and other values if one exists. Read more
This method tests less than (for self and other) and is used by the < operator. Read more
This method tests less than or equal to (for self and other) and is used by the <=
operator. Read more
This method tests greater than (for self and other) and is used by the > operator. Read more