/tmp/ex1-1ed3e5.o: In function `main':
ex1.cpp:(.text+0x9d0): multiple definition of `main'
/tmp/main-cf273f.o:main.cpp:(.text+0x0): first defined here
/tmp/main-cf273f.o: In function `main':
main.cpp:(.text+0x76): undefined reference to `ex1_reverse_array()'
main.cpp:(.text+0x7d): undefined reference to `ex1_ordered_vector()'
main.cpp:(.text+0x84): undefined reference to `ex1_reverse_stack()'
main.cpp:(.text+0x8b): undefined reference to `ex1_ordered_array()'
main.cpp:(.text+0x92): undefined reference to `ex1_reverse_vector()'
main.cpp:(.text+0x99): undefined reference to `ex1_ordered_queue()'
clang: error: linker command failed with exit code 1 (use -v to see invocation)