Ada Reference Manual (Ada 2022)
13.11.1 Storage Allocation Attributes
The Max_Size_In_Storage_Elements and Max_Alignment_For_Allocation attributes may be useful in writing user-defined pool types.
Static Semantics
For every subtype S, the following attributes are defined:
S'Max_Size_In_Storage_Elements
Denotes the maximum value for Size_In_Storage_Elements that can be requested by the implementation via Allocate for an access type whose designated subtype is S. The value of this attribute is of type universal_integer.
S'Max_Alignment_For_Allocation
Denotes the maximum value for Alignment that can be requested by the implementation via Allocate for an access type whose designated subtype is S. The value of this attribute is of type universal_integer.
For a type with access discriminants, if the implementation allocates space for a coextension in the same pool as that of the object having the access discriminant, then these attributes account for any calls on Allocate that can be performed to provide space for such coextensions.
