Range/Loop through N variables in [modern] C++

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What's a succinct way of ranging through N variables of any type to perform an operation?

Let's say I have variables a, b, c, d, e and want to go through all of them performing some operation.

asked 2 mins ago

pepper_chico

2,072

1 Answer

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0

Use Boost.Fusion and generic lambdas:

#include <tuple>
#include <iostream>
#include <boost/fusion/adapted/std_tuple.hpp>
#include <boost/fusion/algorithm/iteration/for_each.hpp>

struct Foo1 {
    int foo() const { return 42; }
};

struct Foo2 {
    int bar = 0;
    int foo() { bar = 24; return bar; }
};

int main() {
    using namespace std;
    using namespace boost::fusion;

    Foo1 foo1;
    Foo2 foo2;

    for_each(tie(foo1, foo2), [](auto &foo) {
        cout << foo.foo() << endl;
    });

    cout << "foo2.bar after mutation: " << foo2.bar << endl;
}

http://ift.tt/1mClUGS

answered 1 min ago

pepper_chico

2,072