4.35 Attribute Library_Level

P'Library_Level, where P is an entity name, returns a Boolean value which is True if the entity is declared at the library level, and False otherwise. Note that within a generic instantition, the name of the generic unit denotes the instance, which means that this attribute can be used to test if a generic is instantiated at the library level, as shown in this example:

generic
  ...
package Gen is
  pragma Compile_Time_Error
    (not Gen'Library_Level,
     "Gen can only be instantiated at library level");
  ...
end Gen;