How to match double stem in target like %/% or other way?

Question

I need to build targets with names like,

v1/thread4/foo  v1/thread8/foo v1/thread16/foo
v2/thread4/foo  v2/thread8/foo v2/thread16/foo

I want

Answer 1

There is no way to have multiple patterns in GNU make.

If your example above is actually reflective of what you want to do, it's simple enough, though:

VLIST := 1 2
TLIST := 4 8 16

TARGETS := $(foreach V,$(VLIST),$(foreach T,$(TLIST),v$V/thread$T/foo))

$(TARGETS): foo.cc $(HEADERS)
        $(CXX) $(CXXFLAGS) -DTHREAD=$* -o $@ $< $(LDLIBS)