CODEWITHSUNDEEP
c++boostboost-function
DuckQueen
DuckQueen

Reputation: 800

How to clear boost function?

Having a non-empty boost::function, how to make it empty (so when you call .empty() on it you'll get true)?

Upvotes: 3

Views: 3807

Answers (2)

Lou
Lou

Reputation: 1955

f.clear() will do the trick. Using the example above

#include <boost/function.hpp>
#include <iostream>

int foo(int) { return 42; }

int main()
{
    boost::function<int(int)> f = foo;
    std::cout << f.empty();

    f.clear();
    std::cout << f.empty();

    f = boost::function<int(int)>();
    std::cout << f.empty();
}

will yield the same result.

Upvotes: 4

jrok
jrok

Reputation: 55395

Simply assign it NULL or a default constructed boost::function (which are empty by default):

#include <boost/function.hpp>
#include <iostream>

int foo(int) { return 42; }

int main()
{
    boost::function<int(int)> f = foo;
    std::cout << f.empty();

    f = NULL;
    std::cout << f.empty();

    f = boost::function<int(int)>();
    std::cout << f.empty();
}

Output: 011

Upvotes: 4

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