Walter Bright:
http://www.drdobbs.com/cpp/implementing-half-floats-in-d/240146674
From the article:
Built-in types tend to run faster because the optimizer can take advantage of mathematical identities,<
Generally in D we like the compiler to verify user-applied annotations like pure and const. For the compiler of a normal language today it's probably too much difficult to prove the theorems coming from those identities on user defined types. But if the compiler assumes the programmer to be right on this (because such types are usually defined in well reviewed libraries), then I think it's not too much hard to invent a small set of @annotations that attached to a user defined struct tell the compiler to allow some optimizations typical of integral numbers, floating point numbers, complex numbers, gaussian integers, quaternions, octonions and few others, according to them having associative, commutative, etc, properties, or not having them.
Bye, bearophile
