To: J3                                                     J3/23-182
From: Brad Richardson
Subject: Intrinsic Requirements
Date: 2023-June-12

#Reference:

Introduction:
-------------

This paper describes intrinsic requirements as a proposed feature for
F202Y.

The templates feature has introduced the concept of a REQUIREMENT,
which serves to encapsulate and reuse sets of declarations. In some
cases it would be desirable to also specify properties of certain
types or values which cannot be specified by a declaration. For example
it would be nice to specify the requirement that a value be a valid kind
for a given intrinsic type. I.e.

REQUIRES VALID_REAL_KIND(K)

This will also potentially serve a role as we allow for polymorphism with
deferred types. I.e.

REQUIRES EXTENDS_FROM(T, U)