Boost Spirit X3 bug

main.cpp

#include <iostream>
#include <boost/spirit/home/x3.hpp>
#include <boost/spirit/home/x3.hpp>
#include <boost/fusion/adapted/struct/adapt_struct.hpp>


namespace x3 = boost::spirit::x3;

struct numbers {
  int value;
  int value2;
  // number& operator=(const int data) {
  //     this->value = data;
  //     return *this;
  // }
};
BOOST_FUSION_ADAPT_STRUCT(numbers, value, value2)

auto doSideEffects = x3::eps[([] (auto& ctx) {
    // do some stuff...
})];

auto wrappedDoSideEffects = x3::rule<class Rule, x3::unused_type>{} = doSideEffects;

auto my_rule = x3::rule<class my_class, numbers>{} = doSideEffects > x3::int32 > " " > x3::int32;

int main(int argc, char* argv[])
{
    std::string input = "235 12";
    numbers out;
    auto it = input.begin();
    auto res = x3::parse(it, input.end(), my_rule, out);
    // This doesn't print 235 and 12, because doSideEffects breaks the parser.
    // If I swap doSideEffects with wrappedDoSideEffects, it works again.
    std::cout << "out.arg = " << out.value << "\n";
    std::cout << "out.arg = " << out.value2 << "\n";

    return 0;
}