Alex Luya <alex_luya@xxxxxxxx> writes: > I download source code for book <</Data Structures and Algorithm > Analysis in C++ (Second Edition), /by Mark Allen Weiss>> > from:http://users.cs.fiu.edu/~weiss/dsaa_c++/code/,try to compiler > it,but got many errors,most of them say: > ...... previously declared here > .......: redefinition of ..... These errors occur also with g++ -c, which does not run the linker; therefore they are compile errors, rather than link errors. First, download the ANSI C++ versions of the source files from <http://users.cs.fiu.edu/~weiss/dsaa_c++/code/ansi/>. The original files are for GCC 2.8.1 and have problems with GCC 4.3.3. Then, do not compile StackAr.cpp separately. That won't work. StackAr.cpp begins with #include "StackAr.h", and there is an #include "StackAr.cpp" near the end of StackAr.h, so you get a loop (although not an infinite loop): StackAr.cpp: #include "StackAr.h" StackAr.h: #ifndef STACKAR_H /* not yet defined */ StackAr.h: #define STACKAR_H StackAr.h: template <class Object> class Stack { ... }; StackAr.h: #include "StackAr.cpp" StackAr.cpp: #include "StackAr.h" StackAr.h: #ifndef STACKAR_H /* now it's already defined */ StackAr.h: /* the contents are therefore ignored */ StackAr.h: #endif StackAr.cpp: ... defines the various functions ... StackAr.h: #endif StackAr.cpp: ... tries to define the same functions again ... Thus, StackAr.cpp should be used only via StackAr.h, never on its own. Perhaps it'd be better to name such files e.g. *.inl rather than *.cpp, to discourage IDEs from attempting to compile them.
