🚀 go-pugleaf

matt@physics2.berkeley.edu (Matt Austern) writes:

: I believe that an exponentiation operator would be of genuine benefit
: to C++ scientific programmers, and I believe that we who write
: scientific code are justified in asking that it be included.  I don't
: think, however, that we are justified in asking for a change to the
: language that makes life harder for other C++ programmers.  Using **
: to denote exponentiation does exactly that: it changes the meaning of
: legal C++ code, and it makes a useful programming technique more
: difficult.
: 
: It is possible to implement an exponentiation operator so that the
: extension to the language will have no effect at all for people who
: don't deliberately use the new feature.  This is a better idea.

Did you consider operator () for exponentiation?
It seems to have correct precedence and doesn't need new tokens to be
introduced.

// if op () is available for exp
double e= -10(2); // e = -100.0
double d=10;
double *p = &e;

e = d(3) - (*p)(2) + d + 3; // e = -8987.0

// status quo
class Double {
	double d;
public:
	Double(double f): d(f) {}
	operator double () { return d; }
	Double operator - () { return -d; }
	Double operator () (int i) { ... }
	Double operator () (double f) { return pow(d,f); }
	// other ops ...
};

Double a(10);  // a = 10.0
double d=a(5); // d = 10000.0

a = a(3.0)*2.5; // a = 2500.0

Double b(2); // b = 2
a = -b(4) + 3*b(3) - 2*b(2) + b + 3; // a = 5.0

Similary you can define your own Int as well and use it wherever
you want int and exp op. 

-Sekar