Pointer types are used by unsafe code to directly address memory. Only pointers to unmanaged value types are supported. This ensures that pointers can be implemented as simple addresses compatible with pointers in languages like C. Reference types may require fat pointers to enable virtual method dispatch. Thus pointers to reference types are not valid.
Pointer types are non-nullable. To represent a nullable pointer use an optional pointer type (i.e.
@int?).
pointer_type
: "@" value_type
| "@" "void"
;
The unmanaged types are any of the simple types except int and uint and structs composed only of
unmanaged types. This ensures that pointers are constructed only to types which do not contain any
garbage collected references. The simple types int and uint are not unmanaged types because even
though they may consist of a locally stored value, when the value they contain grows large, they
often contain a garbage collected reference to the larger number.
The type "@void", is a pointer type that places no limits on what may be at the memory pointed to.
Conversion of a pointer to the void pointer type can be done implicitly. Conversion from a void
pointer to another pointer type requires an explicit cast.