error: ‘usleep‘ was not declared in this scope

编译orb-slam2 错误：

error: 'usleep' was not declared in this scope

step1

修改 ORB_SLAM2/include/system.h

添加：

#include

step2

修改 ORB_SLAM2/include/LoopClosing.h

typedef map,
        Eigen::aligned_allocator > > KeyFrameAndPose;

为

typedef map,
        Eigen::aligned_allocator > > KeyFrameAndPose;