Hi, I'm trying to use boost in a cygwin enviroment. I've installed the boost-1_33_1 libraries using the cygwin setup program. I have a makefile to compile a simple program but I keep getting the error. $ make g++ -c -O3 cash_flow.cpp In file included from cash_flow.cpp:6: cash_flow.h:12: error: `boost' has not been declared cash_flow.h:12: error: ISO C++ forbids declaration of `shared_ptr' with no type cash_flow.h:12: error: expected `;' before '<' token make: *** [cash_flow.o] Error 1 I'm new to Unix like environments and am not able to setup the makefile properly. Below is what I have TARGET = main CPP = g++ CPPFLAGS = -O3 INCLUDES = -I/usr/include/boost-1_33_1 LDFLAGS = LIBS = -lboost_1_33_1 SOURCES = $(wildcard *.cpp) DEPENDS = $(SOURCES:%.cpp=%.d) OBJECTS = $(DEPENDS:%.d=%.o) TMPS = $(wildcard *.hpp~) $(wildcard *.cpp~) $(TARGET) : $(OBJECTS) $(CPP) -o $@ $(LDFLAGS) $(OBJECTS) $(LIBS) clean : rm -rf $(TARGET) $(DEPENDS) $(OBJECTS) $(TMPS) $(DEPENDS) : %.d : %.cpp set -e; $(CPP) -MM $(CPPFLAGS) $< \ | sed 's/\($*\)\.o[ :]*/\1.o $@ : /g' > $@; \ [ -s $@ ] || rm -f $@ $(OBJECTS) : %.o : %.cpp $(CPP) -c $(CPPFLAGS) $< .PHONY : clean include $(DEPENDS) I also tried using the includes/library names I tried that as well INCLUDES = -I/usr/include/boost-1_33_1 LDFLAGS = -L/usr/lib LIBS = -lboost_1_33_1 and $(OBJECTS) : %.o : %.cpp $(CPP) -c $(CPPFLAGS) $(INCLUDES) $< Still get the same error .. Can someone tell me which libboost*.a should I point to as there are many .. for eg to use boost::shared_ptr? Thanks S.