c++ 怎么看懂opencv 里函数的异常

Question

除了一个个找typedef没其他办法了吗，有没有文档是直接解释的？

_Tp& Mat::at(int i0, int i1)
{

CV_DbgAssert(dims <= 2);
CV_DbgAssert(data);
CV_DbgAssert((unsigned)i0 < (unsigned)size.p[0]);
CV_DbgAssert((unsigned)(i1 * DataType<_Tp>::channels) < (unsigned)(size.p[1] * channels()));
CV_DbgAssert(CV_ELEM_SIZE1(DataType<_Tp>::depth) == elemSize1());  //看不懂
return ((_Tp*)(data + step.p[0] * i0))[i1];

}