On 7/24/15 2:05 AM, H. S. Teoh via Digitalmars-d wrote:
Well, this is where the whole idea of Concepts comes from. Rather than
specify the nitty-gritty of exactly which operations the type must
support, you introduce an abstraction called a Concept, which basically
is a group of related traits that a type must satisfy. You can think of
it as a prototypical "type" that supports all the required operations.
For example, an input range would be a Concept that supports the
operations .front, .empty, and .popFront. A forward range would be a
larger Concept derived from the input range Concept, that adds the
operation .save.
Your range functions don't have to specify explicitly that "type T must
have methods called .empty, .front, .popFront", they simply say "type T
must conform to the InputRange Concept".
As I argued in "Generic Programming Must Go", this does work on
scarce-vocabulary domain. The moment you start talking about ranges that
may or may not support cross-cutting primitives, it all comes unglued.
-- Andrei
