The BOOST_PP_FILENAME_x macro is a user-defined named external argument used by BOOST_PP_ITERATE. 
		It denotes the file to be iterated over.
	
	Usage
		
			#define BOOST_PP_FILENAME_x filename
		
	Arguments
		
			- x
- 
				The iteration depth of the next file-iteration. 
				This value must be the current iteration depth + 1.
			
- filename
- 
				A quoted or angle-bracketed filename to used as the target of a file-iteration.
			
Remarks
		
			This macro is part of the secondary method of passing arguments to BOOST_PP_ITERATE. 
			The other part is BOOST_PP_ITERATION_LIMITS.
		
		
			This macro is automatically undefined for reuse by a call to BOOST_PP_ITERATE.
		
	See Also