As [1] explained, the real debug message will be like:
"res operator(): operator() : queue result stop"
Set the name explicitly, the message is easy for debugging:
"res operator(): recv : queue result stop"
The left "operator()" is generated by 'RES_DBG() ... __func__'
[1]: https://clang.llvm.org/extra/clang-tidy/checks/bugprone/lambda-function-name.html
Signed-off-by: Haiyue Wang <haiyuewa@163.com>