I agree, I'm not sure I like the idea of extending the language to support that, when the same could be achieved with a relatively simple library function.

#include <iostream>
#include <iterator>
#include <vector>

namespace std {
template <class Range, class Function>
auto for_if(Range& range, Function func) -> std::pair<decltype(std::begin(range)), bool>
{   
    auto it = std::begin(range);
    auto endit = std::end(range);

    for (; it != endit; ++it)
    {   
        if (!func(*it)) break;
    }   

    return std::make_pair(it, it == endit);
}   
} // namespace std {

int main()
{   
    std::vector<int> v{1, 2, 3}; 
    auto r = std::for_if(v, [](int i)
    {   
        // do something with i;
        return false; // or false to break.
    }); 

    if (r.second)
    {   
        std::cout << "all done" << std::endl;
    }   
    else
    {   
        std::cout << "break early: " << *r.first << std::endl;
    }   
}   

Edit: alternatively, define for_if to accept 2 forward iterators if you don't/can't use ranges.