Using boost::bind to bind member-function to boost::bisect?

Question

I\'ve had problems with this before but now it\'s somehow working.

Now I\'ve following problem. I need to bind values into member-function before I call boost::bisect wi

Answer 1

This code:

std::pair<double, double> result = bisect(boost::bind(&CLASS::Function,this, _1), 0.0, 1.000000, TerminationCondition());

is correct. The error you get means that what CLASS::Function returns is invalid. bisect is complaining about multiple roots (or possibly no roots) in the given interval [0; 1]. How does CLASS::Function look like?

Answer 2

If I read the tutorial correctly, it should be:

std::pair<double, double> result =
    bisect(boost::bind(&CLASS::Function, this, _1, _2, _3),
        0.0, 1.000000, TerminationCondition());

I.e. the parameters to boost::bind() are:

1. The name of the function (object) to bind to
2. the arguments to pass to that, as the function expects them

For your case, a CLASS::memberFunc(), that'd be a CLASS * (possibly this but any CLASS * is ok) as the first, which you literally state as such, followed by the parameters later passed to the bound object.

These "futures" are designated by _1, _2 and so on, depending on their position at invocation time.

Example:

class addthree {
private:
    int second;
public:
    addthree(int term2nd = 0) : second(term2nd) {}
    void addto(int &term1st, const int constval) {
        term1st += (term2nd + constval);
    }
}

int a;
addthree aa;
boost::function<void(int)> add_to_a = boost::bind(&addthree::addto, &aa, a, _1);
boost::function<void(void)> inc_a = boost::bind(&addthree::addto, &aa, a, 1);

a = 0 ; add_to_a(2); std::cout << a << std::endl;
a = 10; add_to_a(a); std::cout << a << std::endl;
a = 0 ; inc_a(); std::cout << a << std::endl;
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