TestFunctions.o: In function `testBorrowBook()':
/in/compile/TestFunctions.cpp:106: undefined reference to `library::library()'
TestFunctions.o: In function `testReturnBook()':
/in/compile/TestFunctions.cpp:125: undefined reference to `library::library()'
TestFunctions.o: In function `test12()':
/in/compile/TestFunctions.cpp:195: undefined reference to `library::library()'
TestFunctions.o: In function `test13()':
/in/compile/TestFunctions.cpp:217: undefined reference to `library::library()'
TestFunctions.o: In function `test14()':
/in/compile/TestFunctions.cpp:227: undefined reference to `library::library()'
TestFunctions.o:/in/compile/TestFunctions.cpp:237: more undefined references to `library::library()' follow
collect2: error: ld returned 1 exit status
/in/compile/Makefile:18: recipe for target 'test' failed
make: *** [test] Error 1