Valgrind在Stringstream中显示可达泄漏

Question

我正在使用“ std :: stringstream”将“ long”值转换为“ hex-string”，以便在代码中进一步使用。

程式码片段如下：

void initDisplayVariant(){
    ...
    /// integer value to hex-string
    std::stringstream sstream;
    sstream << "0x"
            << std::setfill ('0') << std::setw(2)
    << std::hex << (int)frntDispVariant;
    std::string frntDispVariantHex = sstream.str();
    sstream.clear();    //clears out the stream-string
    ...
}

但是，valgrind在“可达泄漏”中列出了位置。

...
==6736== 0 bytes in 1 blocks are still reachable in loss record 1 of 143
==6736==    at 0x4024045: operator new[](unsigned int) (vg_replace_malloc.c:299)
==6736==    by 0x5232570: std::__numpunct_cache<char>::_M_cache(std::locale const&) (in /usr/lib/libstdc++.so.6.0.14)
==6736==    by 0x5236684: std::ostreambuf_iterator<char, std::char_traits<char> > std::num_put<char, std::ostreambuf_iterator<char, std::char_traits<char> > >::_M_insert_int<long>(std::ostreambuf_iterator<char, std::char_traits<char> >, std::ios_base&, char, long) const (in /usr/lib/libstdc++.so.6.0.14)
==6736==    by 0x523678D: std::num_put<char, std::ostreambuf_iterator<char, std::char_traits<char> > >::do_put(std::ostreambuf_iterator<char, std::char_traits<char> >, std::ios_base&, char, long) const (in /usr/lib/libstdc++.so.6.0.14)
==6736==    by 0x5241B43: std::ostream& std::ostream::_M_insert<long>(long) (in /usr/lib/libstdc++.so.6.0.14)
==6736==    by 0x5241CB4: std::ostream::operator<<(int) (in /usr/lib/libstdc++.so.6.0.14)
==6736==    by 0x808E76B: initDisplayVariant() (src.cpp:45)
...

由于流是方法本地的，并且不应超出方法的范围存在（即使它在内部进行分配），因此，报告泄漏的上下文尚不清楚。

有什么线索或建议吗？