ISO C++ forbids declaration of 'PortSettings' with no typeexpected ',' or '...' before '*' token

头文件中有这句： QMainComThread(QString name, const PortSettings *settings);
cpp文件中 
QMainComThread::QMainComThread(QString name, const PortSettings *settings)
{
  comsettings = new PortSettings();
  *comsettings = *settings;
  comname = name;
  comport = NULL;
} 但是提示错误 ISO C++ forbids declaration of 'PortSettings' with no type
  expected ',' or '...' before '*' token
  return type specification for constructor invalid 求解。。。

PortSettings类的头文件没有包含？在头文件类之前加上 class PortSettings；试试