installing a header fails implicit rule search

[Edgar]

I can't get my header install targets to work correctly. My implicit 
rule doesn't match my prerequisites. I made as small an example as I 
could, here it is :


INSTALLEDHEADERS = folder\test.hpp

.PHONY : install
install : $(INSTALLEDHEADERS)

folder\%.hpp : %.hpp
   copy $< $@



Here's the output of make install :

c:\ctwoplus\progcode\allegro\Eagle\maketest>make install
make: *** No rule to make target `folder\test.hpp', needed by 
`install'.  Stop.

So, why doesn't folder\%.hpp match folder\test.hpp? I don't get it.

Nevermind, I figured it out - if I replace all the backslashes with 
forward slashes and then change the copy command to use backslashes by a 
$(substr /,$(SLASH),$(FOO)) substitution, it all works. Maybe this post 
will help someone in the future. I figured mingw32-make would be able to 
handle backslashes. Guess not.