1 files changed, 8 insertions, 4 deletions

diff --git a/Makefile b/Makefile
index 8a2f666..15de4d0 100644
--- a/Makefile
+++ b/Makefile
@@ -1,3 +1,5 @@
+# references:
+#    BUILD_DIR and per-.cpp file https://spin.atomicobject.com/2016/08/26/makefile-c-projects/
 awkbin     :=$(shell which awk)
 cpbin      :=$(shell which cp)
 echobin    :=$(shell which echo)
@@ -20,13 +22,15 @@ LDFLAGS = -g
 src = $(wildcard *.cpp)
 obj = $(src:.cpp=.o)
 
-OUTEXE = helloworld
+BUILD_DIR ?= .
+
+OUTEXE = mine
 
 all: $(OUTEXE)
 
-# compile
-$(obj): $(src)
-	$(CXX) -c $(CXXFLAGS) $<
+# compile, which is not actually used?
+$(BUILD_DIR)%.o: %.cpp
+	$(CXX) -c $(CXXFLAGS) $+
 
 # link
 $(OUTEXE): $(obj)