Mark Mitchell wrote:-
However, while that may be necessary for Java, it's not necessary for
C++. In C++, fold should only be called for "integral constant
expressions", which, by definition, are made up of simple operations on
integers. (It's a little more complicated than that, but all the
operands collapse to integers immediately.) So, all we really need for
C++ is the ability to convert floating-point constants to integer
constants, and the ability to do basic arithmetic on integer constants.
I think it's desirable for front-ends to be able to fold floating
point constant expressions too, no? It can be handy for diagnostics
such as detecting overflow or unreachable code based on conditionals
whose expression is a floating one, albeit constant.