12.5.3 Formal Array Types
The category determined for a formal array type is
the category of all array types.
For a formal array
subtype, the actual subtype shall satisfy the following conditions:
The formal array type and the actual array type
shall have the same dimensionality; the formal subtype and the actual
subtype shall be either both constrained or both unconstrained.
For each index position, the index types shall
be the same, and the index subtypes (if unconstrained), or the index
ranges (if constrained), shall statically match (see 4.9.1
The component subtypes of the formal and actual
array types shall statically match.
If the formal type has aliased components, then
so shall the actual.
Example of formal
-- given the generic package
type Item is private;
type Index is (<>);
type Vector is array (Index range <>) of Item;
type Table is array (Index) of Item;
package P is
-- and the types
type Mix is array (Color range <>) of Boolean;
type Option is array (Color) of Boolean;
-- then Mix can match Vector and Option can match Table
package R is new P(Item => Boolean, Index => Color,
Vector => Mix, Table => Option);
-- Note that Mix cannot match Table and Option cannot match Vector
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