I have the following problem when I try to call method in &quot;TestSerialize&quot; class during serialization process.<div><br></div><div>Here is my code:</div><div><br></div><div><div>class TestSerialize</div><div>{</div>

<div>public:</div><div>    std::string GetVal() { return Val + &quot;abc&quot;; }</div><div>    void SetVal(std::string tVal) { Val = tVal.substr(0, 2); }</div><div><br></div><div>protected:</div><div><br></div><div>    std::string Val;</div>

<div><br></div><div>    friend class boost::serialization::access;</div><div>    template&lt;class Archive&gt; void save(Archive &amp; ar, const unsigned int version) const</div><div>    {</div><div>        using boost::serialization::make_nvp;</div>

<div>        std::string tVal = GetVal(); // Error here</div><div>        ar &amp; make_nvp(&quot;SC&quot;, tVal);</div><div>    }</div><div><br></div><div>    template&lt;class Archive&gt; void load(Archive &amp; ar, const unsigned int version)</div>

<div>    {</div><div>        using boost::serialization::make_nvp;</div><div>        std::string tVal;</div><div>        ar &amp; make_nvp(&quot;SC&quot;, tVal);</div><div>        SetVal(tVal);</div><div>    }</div><div>
    BOOST_SERIALIZATION_SPLIT_MEMBER();</div>
<div>};</div><div><br></div><div>int main()</div><div>{</div><div>    TestSerialize tS;</div><div><br></div><div>    std::ofstream ofs(&quot;test.xml&quot;);</div><div>    boost::archive::xml_oarchive oa(ofs, boost::archive::no_header);</div>

<div>    oa &lt;&lt; BOOST_SERIALIZATION_NVP(tS);</div><div>    ofs.close();</div><div><br></div><div>    return 0;</div><div>}</div></div><div><br></div><div>The error that I encountered is: </div><div>&#39;TestSerialize::GetVal&#39; : cannot convert &#39;this&#39; pointer from &#39;const TestSerialize&#39; to &#39;TestSerialize &amp;&#39;</div>

<div><br></div><div>This error only happens on &quot;save&quot; but not &quot;load&quot;</div><div><br></div><div>I wonder why I get this error. I would like to know what Boost.Serialization do such that we have these two different behaviors.</div>

<div>I use Boost Library 1.47.0</div><div><br></div><div><br></div><div>Regards,</div>