fix: build failed with Qt5.11 and GCC8.3.

[re2zero]

the header ‘’ was included QDebug, if miss include functional or Debug, it would error: ‘std::function’ has not been declared.

Log: fix build failed issue.

[re2zero]

build error logs:

:~/work/demo/scrcpy/QtScrcpy-new/build$ cmake ..
-- [QtScrcpy] Project QtScrcpy 0.0.0
-- [QtScrcpy] CPU_ARCH:x64
-- [QtScrcpy] BUILD_TYPE:RelWithDebInfo
-- [QtScrcpy] C++ compiler ID is: GNU
-- [QtScrcpy] Set warnings as error
-- [QtScrcpy] Qt version is: 5.11
-- multi config:QC_IS_MUTIL_CONFIG
-- [QtScrcpy] QSC_CPU_ARCH:x64
-- [QtScrcpyCore] QSC_DEPLOY_PATH: /home/doll/work/demo/scrcpy/QtScrcpy-new/QtScrcpy/../output/x64/RelWithDebInfo/$<0:>
-- Configuring done
-- Generating done
-- Build files have been written to: /home/doll/work/demo/scrcpy/QtScrcpy-new/build
doll@doll-PC:~/work/demo/scrcpy/QtScrcpy-new/build$ make
[  2%] Automatic MOC and UIC for target QtScrcpyCore
[  2%] Built target QtScrcpyCore_autogen
[  4%] Building CXX object QtScrcpy/QtScrcpyCore/CMakeFiles/QtScrcpyCore.dir/QtScrcpyCore_autogen/mocs_compilation.cpp.o
[  6%] Building CXX object QtScrcpy/QtScrcpyCore/CMakeFiles/QtScrcpyCore.dir/src/adb/adbprocessimpl.cpp.o
[  9%] Building CXX object QtScrcpy/QtScrcpyCore/CMakeFiles/QtScrcpyCore.dir/src/adb/adbprocess.cpp.o
[ 11%] Building CXX object QtScrcpy/QtScrcpyCore/CMakeFiles/QtScrcpyCore.dir/src/device/device.cpp.o
[ 13%] Building CXX object QtScrcpy/QtScrcpyCore/CMakeFiles/QtScrcpyCore.dir/src/device/controller/controller.cpp.o
[ 15%] Building CXX object QtScrcpy/QtScrcpyCore/CMakeFiles/QtScrcpyCore.dir/src/device/controller/bufferutil.cpp.o
[ 18%] Building CXX object QtScrcpy/QtScrcpyCore/CMakeFiles/QtScrcpyCore.dir/src/device/controller/inputconvert/inputconvertbase.cpp.o
[ 20%] Building CXX object QtScrcpy/QtScrcpyCore/CMakeFiles/QtScrcpyCore.dir/src/device/controller/inputconvert/inputconvertnormal.cpp.o
[ 22%] Building CXX object QtScrcpy/QtScrcpyCore/CMakeFiles/QtScrcpyCore.dir/src/device/controller/inputconvert/inputconvertgame.cpp.o
[ 25%] Building CXX object QtScrcpy/QtScrcpyCore/CMakeFiles/QtScrcpyCore.dir/src/device/controller/inputconvert/controlmsg.cpp.o
[ 27%] Building CXX object QtScrcpy/QtScrcpyCore/CMakeFiles/QtScrcpyCore.dir/src/device/controller/inputconvert/keymap/keymap.cpp.o
[ 29%] Building CXX object QtScrcpy/QtScrcpyCore/CMakeFiles/QtScrcpyCore.dir/src/device/controller/receiver/devicemsg.cpp.o
[ 31%] Building CXX object QtScrcpy/QtScrcpyCore/CMakeFiles/QtScrcpyCore.dir/src/device/controller/receiver/receiver.cpp.o
[ 34%] Building CXX object QtScrcpy/QtScrcpyCore/CMakeFiles/QtScrcpyCore.dir/src/device/decoder/avframeconvert.cpp.o
[ 36%] Building CXX object QtScrcpy/QtScrcpyCore/CMakeFiles/QtScrcpyCore.dir/src/device/decoder/decoder.cpp.o
[ 38%] Building CXX object QtScrcpy/QtScrcpyCore/CMakeFiles/QtScrcpyCore.dir/src/device/decoder/fpscounter.cpp.o
[ 40%] Building CXX object QtScrcpy/QtScrcpyCore/CMakeFiles/QtScrcpyCore.dir/src/device/decoder/videobuffer.cpp.o
In file included from /home/doll/work/demo/scrcpy/QtScrcpy-new/QtScrcpy/QtScrcpyCore/src/device/decoder/videobuffer.cpp:1:
/home/doll/work/demo/scrcpy/QtScrcpy-new/QtScrcpy/QtScrcpyCore/src/device/decoder/videobuffer.h:38:33: error: ‘std::function’ has not been declared
     void peekRenderedFrame(std::function<void(int width, int height, uint8_t* dataRGB32)> onFrame);
                                 ^~~~~~~~
/home/doll/work/demo/scrcpy/QtScrcpy-new/QtScrcpy/QtScrcpyCore/src/device/decoder/videobuffer.h:38:41: error: expected ‘,’ or ‘...’ before ‘<’ token
     void peekRenderedFrame(std::function<void(int width, int height, uint8_t* dataRGB32)> onFrame);
                                         ^
/home/doll/work/demo/scrcpy/QtScrcpy-new/QtScrcpy/QtScrcpyCore/src/device/decoder/videobuffer.cpp:110:42: error: variable or field ‘peekRenderedFrame’ declared void
 void VideoBuffer::peekRenderedFrame(std::function<void(int width, int height, uint8_t* dataRGB32)> onFrame)
                                          ^~~~~~~~
/home/doll/work/demo/scrcpy/QtScrcpy-new/QtScrcpy/QtScrcpyCore/src/device/decoder/videobuffer.cpp:110:42: error: ‘function’ is not a member of ‘std’
/home/doll/work/demo/scrcpy/QtScrcpy-new/QtScrcpy/QtScrcpyCore/src/device/decoder/videobuffer.cpp:110:42: note: ‘std::function’ is defined in header ‘<functional>’; did you forget to ‘#include <functional>’?
/home/doll/work/demo/scrcpy/QtScrcpy-new/QtScrcpy/QtScrcpyCore/src/device/decoder/videobuffer.cpp:8:1:
+#include <functional>
 }
/home/doll/work/demo/scrcpy/QtScrcpy-new/QtScrcpy/QtScrcpyCore/src/device/decoder/videobuffer.cpp:110:42:
 void VideoBuffer::peekRenderedFrame(std::function<void(int width, int height, uint8_t* dataRGB32)> onFrame)
                                          ^~~~~~~~
/home/doll/work/demo/scrcpy/QtScrcpy-new/QtScrcpy/QtScrcpyCore/src/device/decoder/videobuffer.cpp:110:97: error: expression list treated as compound expression in functional cast [-fpermissive]
 void VideoBuffer::peekRenderedFrame(std::function<void(int width, int height, uint8_t* dataRGB32)> onFrame)
                                                                                                 ^
/home/doll/work/demo/scrcpy/QtScrcpy-new/QtScrcpy/QtScrcpyCore/src/device/decoder/videobuffer.cpp:110:51: error: expected primary-expression before ‘void’
 void VideoBuffer::peekRenderedFrame(std::function<void(int width, int height, uint8_t* dataRGB32)> onFrame)
                                                   ^~~~
cc1plus: error: unrecognized command line option ‘-Wno-c++17-extensions’ [-Werror]
cc1plus: error: unrecognized command line option ‘-Wno-nested-anon-types’ [-Werror]
cc1plus: all warnings being treated as errors
make[2]: *** [QtScrcpy/QtScrcpyCore/CMakeFiles/QtScrcpyCore.dir/build.make:300：QtScrcpy/QtScrcpyCore/CMakeFiles/QtScrcpyCore.dir/src/device/decoder/videobuffer.cpp.o] 错误 1
make[1]: *** [CMakeFiles/Makefile2:170：QtScrcpy/QtScrcpyCore/CMakeFiles/QtScrcpyCore.dir/all] 错误 2
make: *** [Makefile:91：all] 错误 2

In order to clear the highlight editing warning in Qt creator, I add '' in these header files.