From: John Maddock (john_at_[hidden])
Date: 2006-02-11 08:43:11
> epsilon should be a constant known at compile time?
> But is the compile unable to know this?
Static assertions require an integral-constant expression, and epsilon is
basically a runtime constant (at best it's a floating point constant).
BTW I don't believe you can portably use DBL_EPSILON etc in a static
assertion: you certainly can't use the DBL_* macros in preprocessor
directives as I've found to my cost already. A vendor is entitled to
implement this as:
#define DBL_EPSILON __dbl_eps
extern const double __dbl_eps;
> Other suggestions on how to achieve a compile-time warning here?
Not really, other than checking for numeric_limits<>::is_specialized.
John.