Std::vector to TArray

I am trying to convert this line of code in to UE4 C++

//std::vector lines;
//size_t numObstLines;

std::vector<Line> projLines(lines.begin(), lines.begin() + static_cast<ptrdiff_t>(numObstLines));

How would I convert this std::vector constructor in to TArray syntax ?
Like if I had a :

//TArray<FLine> lines;
//int32 numObstLines;

TArray<FLine> projLines(???);

Assuming numObstLines is the number of elements to copy from lines then you can do

TArray<FLine> projLines(lines.GetData(), numObstLines);