"multiple initializations given for base" compilation error when trying to extract states into different files

[davidfrulm]

I am trying to split a SML fsm into different files.

ValueToCheck.hpp

#pragma once

struct ValueToCheck { int value; };

States.hpp

#pragma once

#include "ValueToCheck.hpp"
#include <functional>

struct CheckState
{
    static const std::function<bool(const ValueToCheck&)> isBelow5;
    static const std::function<bool(const ValueToCheck&)> isAbove5;
    static const std::function<void()> below5;
    static const std::function<void()> above5;
    static const std::function<void()> exactly5;
};

States.cpp

#include "States.hpp"

#include <iostream>

const std::function<bool(const ValueToCheck&)> CheckState::isBelow5 = [](const ValueToCheck& v) { return v.value < 5; };
const std::function<bool(const ValueToCheck&)> CheckState::isAbove5 = [](const ValueToCheck& v) { return v.value > 5; };
 
const std::function<void()> CheckState::below5 = [] { std::cout << "CheckState::Is below 5" << std::endl; };
const std::function<void()> CheckState::above5 = [] { std::cout << "CheckState::Is above 5" << std::endl; };
const std::function<void()> CheckState::exactly5 = [] { std::cout << "CheckState:.Is exactly 5" << std::endl; };

main.cpp

#include "States.hpp"
#include <boost/sml.hpp>

namespace sml = boost::sml;

struct duplicate_base_type {
    auto operator()() const noexcept {
        using namespace boost::sml;

        return make_transition_table(
            * "CheckState1"_s + event<ValueToCheck> [CheckState::isBelow5] / CheckState::below5 = "CheckState2"_s
            , "CheckState1"_s + event<ValueToCheck> [CheckState::isAbove5] / CheckState::above5 = "CheckState2"_s
            , "CheckState1"_s + event<ValueToCheck> / CheckState::exactly5 = "CheckState2"_s

//            , "CheckState2"_s + event<ValueToCheck> [CheckState::isBelow5] / CheckState::below5 = "CheckState3"_s 
            , "CheckState2"_s + event<ValueToCheck> [CheckState::isAbove5] / CheckState::above5 = "CheckState3"_s
            , "CheckState2"_s + event<ValueToCheck> / CheckState::exactly5 = "CheckState3"_s

//            , "CheckState3"_s + event<ValueToCheck> [CheckState::isBelow5] / CheckState::below5 = X 
            , "CheckState3"_s + event<ValueToCheck> [CheckState::isAbove5] / CheckState::above5 = X
            , "CheckState3"_s + event<ValueToCheck> / CheckState::exactly5 = X

        );
    }
};

int main()
{
    ValueToCheck value_4{4}, value_5{5}, value_6{6};

    boost::sml::sm<duplicate_base_type> sm;
    sm.process_event(value_4); 
    sm.process_event(value_6); 
    sm.process_event(value_5); 
}

My problem occurs when I try to compile either of the commented out lines in the transition table.

Error in one case [ "CheckState2"_s] is as follows:

/var/fpwork/demxfqu6/examples/double_anonymous_transition/../sml-1.1.0/include/boost/sml.hpp:376:12: error: multiple initializations given for base \u2018boost::sml::v1_1_0::aux::pool_type<boost::sml::v1_1_0::front::transition<boost::sml::v1_1_0::front::state<boost::sml::v1_1_0::aux::string<char, 'C', 'h', 'e', 'c', 'k', 'S', 't', 'a', 't', 'e', '3'> >, boost::sml::v1_1_0::front::state<boost::sml::v1_1_0::aux::string<char, 'C', 'h', 'e', 'c', 'k', 'S', 't', 'a', 't', 'e', '2'> >, boost::sml::v1_1_0::front::event<ValueToCheck>, boost::sml::v1_1_0::aux::zero_wrapper<std::function<bool(const ValueToCheck&)>, void>, boost::sml::v1_1_0::aux::zero_wrapper<std::function<void()>, void> > >\u2019 explicit pool(Ts... ts) : pool_type<Ts>(ts)... {}

Error in the other case [ "CheckState3"_s] is as follows:

/var/fpwork/demxfqu6/examples/double_anonymous_transition/../sml-1.1.0/include/boost/sml.hpp:376:12: error: multiple initializations given for base \u2018boost::sml::v1_1_0::aux::pool_type<boost::sml::v1_1_0::front::transition<boost::sml::v1_1_0::front::stateboost::sml::v1_1_0::back::terminate_state, boost::sml::v1_1_0::front::state<boost::sml::v1_1_0::aux::string<char, 'C', 'h', 'e', 'c', 'k', 'S', 't', 'a', 't', 'e', '3'> >, boost::sml::v1_1_0::front::event<ValueToCheck>, boost::sml::v1_1_0::aux::zero_wrapper<std::function<bool(const ValueToCheck&)>, void>, boost::sml::v1_1_0::aux::zero_wrapper<std::function<void()>, void> > >\u2019

Any idea what is going on?