/usr/lib/gcc/x86_64-linux-gnu/6/../../../x86_64-linux-gnu/Scrt1.o: In function `_start':
(.text+0x20): undefined reference to `main'
/tmp/cctsBmkL.o: In function `Search2(int, int, int*, bool)':
foo.cc:(.text+0x432): undefined reference to `Search(int, bool)'
foo.cc:(.text+0x418): undefined reference to `Search(int, bool)'
collect2: error: ld returned 1 exit status