Command
QisLib_GetLayerList

QisLib_GetLayerList

Function:
	int QisLib_GetLayerList(CQisLayer** LayerListPtr);

Inputs:
	LayerListPtr: Address of a pointer of type CQisLayer*. When the function returns
	successfully, this pointer will point to a list of layers.

Return:
	success: value > 0 indicating number of layers present in the list.
	special: 0 indicating no layers were found or no GDSII/OASIS file is opened.
	failure: value < 0 indicating one of the following errors:

Errors:
	-1: Input argument is invalid (null).
	-2: Internal memory error occurred while generating the list of layers.
	-3: File open in progress, operation not permitted.

Description:
	- Gets a list of all layers present in the file.
	- It is the responsibility of the user to ensure that the memory allocated for the
	list is freed by a call to QisLib_FreeLayerList.

Example:
	CQisLayer* List;
	Ret = QisLib_GetLayerList(&List);
	...
	QisLib_FreeLayerList(List);