warning: moving a temporary object prevents copy elision

[osrf-migration]

Original report (archived issue) by yurivict (Bitbucket: yurivict).

---

[10/18] /usr/bin/c++  -Dignition_fuel_tools1_EXPORTS -I/usr/ports/misc/ignition-fuel-tools/work/ignitionrobotics-ign-fuel-tools-cc74edb0c839b613e6bbf5451852457b4dd6357c/include -Iinclude -Icore/include -isystem /usr/local/include/ignition/common3 -isystem /usr/local/include/uuid -isystem /usr/local/include -isystem /usr/local/include/jsoncpp -O2 -pipe -fno-omit-frame-pointer -fstack-protector -fno-strict-aliasing -fno-omit-frame-pointer -O2 -pipe -fno-omit-frame-pointer -fstack-protector -fno-strict-aliasing -fno-omit-frame-pointer  -Wall -Wextra -Wno-long-long -Wno-unused-value -Wfloat-equal -Wshadow -Winit-self -Wswitch-default -Wmissing-include-dirs -pedantic  -fPIC   -msse -msse2 -mfpmath=sse -I/usr/local/include/uuid -I/usr/local/include -I/usr/local/include/jsoncpp -std=c++14 -MD -MT src/CMakeFiles/ignition-fuel_tools1.dir/ModelIter.cc.o -MF src/CMakeFiles/ignition-fuel_tools1.dir/ModelIter.cc.o.d -o src/CMakeFiles/ignition-fuel_tools1.dir/ModelIter.cc.o -c /usr/ports/misc/ignition-fuel-tools/work/ignitionrobotics-ign-fuel-tools-cc74edb0c839b613e6bbf5451852457b4dd6357c/src/ModelIter.cc
/usr/ports/misc/ignition-fuel-tools/work/ignitionrobotics-ign-fuel-tools-cc74edb0c839b613e6bbf5451852457b4dd6357c/src/ModelIter.cc:39:10: warning: moving a temporary object prevents copy elision [-Wpessimizing-move]
  return std::move(ModelIter(std::move(priv)));
         ^
/usr/ports/misc/ignition-fuel-tools/work/ignitionrobotics-ign-fuel-tools-cc74edb0c839b613e6bbf5451852457b4dd6357c/src/ModelIter.cc:39:10: note: remove std::move call here
  return std::move(ModelIter(std::move(priv)));
         ^~~~~~~~~~                          ~
/usr/ports/misc/ignition-fuel-tools/work/ignitionrobotics-ign-fuel-tools-cc74edb0c839b613e6bbf5451852457b4dd6357c/src/ModelIter.cc:46:10: warning: moving a temporary object prevents copy elision [-Wpessimizing-move]
  return std::move(ModelIter(std::move(priv)));
         ^
/usr/ports/misc/ignition-fuel-tools/work/ignitionrobotics-ign-fuel-tools-cc74edb0c839b613e6bbf5451852457b4dd6357c/src/ModelIter.cc:46:10: note: remove std::move call here
  return std::move(ModelIter(std::move(priv)));
         ^~~~~~~~~~                          ~
/usr/ports/misc/ignition-fuel-tools/work/ignitionrobotics-ign-fuel-tools-cc74edb0c839b613e6bbf5451852457b4dd6357c/src/ModelIter.cc:55:10: warning: moving a temporary object prevents copy elision [-Wpessimizing-move]
  return std::move(ModelIter(std::move(priv)));
         ^
/usr/ports/misc/ignition-fuel-tools/work/ignitionrobotics-ign-fuel-tools-cc74edb0c839b613e6bbf5451852457b4dd6357c/src/ModelIter.cc:55:10: note: remove std::move call here
  return std::move(ModelIter(std::move(priv)));
         ^~~~~~~~~~                          ~
/usr/ports/misc/ignition-fuel-tools/work/ignitionrobotics-ign-fuel-tools-cc74edb0c839b613e6bbf5451852457b4dd6357c/src/ModelIter.cc:62:10: warning: moving a temporary object prevents copy elision [-Wpessimizing-move]
  return std::move(ModelIter(std::move(priv)));
         ^
/usr/ports/misc/ignition-fuel-tools/work/ignitionrobotics-ign-fuel-tools-cc74edb0c839b613e6bbf5451852457b4dd6357c/src/ModelIter.cc:62:10: note: remove std::move call here
  return std::move(ModelIter(std::move(priv)));
         ^~~~~~~~~~                          ~
4 warnings generated.

FreeBSD 11.2
clang-6