return type of functions incorrect

[anonymous]

maybe only documented incorrectly, but given the error messages it still takes a few years to figure that out.

e.g. push_back, documented as: typename result_of::push_back<Sequence, T>::type push_back(

Sequence const& seq, T const& t);

when it's actually typename result_of::push_back<Sequence const, T>::type

push_back(Sequence const& seq, T const& x)

note the const. I'm not sure why the const is there, but if it is really intended that: result_of::push_back<seq_t,int>::type res=push_back(seq,4); should result in an error, this should be a major part of the documentation.

[Steven Watanabe]

Actually, I think it would be better if fusion::push_back were overloaded to allow either const or non-const arguments, like

    template <typename Sequence, typename T>
    inline typename result_of::push_back<Sequence, T>::type
    push_back(Sequence & seq, T const& x);

    template <typename Sequence, typename T>
    inline typename result_of::push_back<Sequence const, T>::type
    push_back(Sequence const& seq, T const& x);

Regardless, result_of::push_back ought to work correctly for non-const arguments. If push_back always adds const, then so should result_of::push_back.

[Kohei Takahashi <flast@…>]

Fixed by ​https://github.com/boostorg/fusion/pull/106 .

Replying to steven_watanabe:

Actually, I think it would be better if fusion::push_back were overloaded to allow either const or non-const arguments, like

    template <typename Sequence, typename T>
    inline typename result_of::push_back<Sequence, T>::type
    push_back(Sequence & seq, T const& x);

    template <typename Sequence, typename T>
    inline typename result_of::push_back<Sequence const, T>::type
    push_back(Sequence const& seq, T const& x);

It will be handled in #3954.

[Kohei Takahashi <flast@…>]

Joel, could you close this ticket?