I have a very simple C++ file Multiplier.cpp with the corresponding header file, from which I have created a library using the following commands
$ g++ -o Multiplier.o -c Multiplier.cpp
$ ar cr libMultiplier.a Multiplier.o
In a new directory, I have created a Calculator.cpp (with corresponding header file) which uses the Multiplier class. the header file Calculator.h has the corresponding `#include "Multiplier.h"
The header file Calculator.h has the corresponding #include "Multiplier.h"
I copied the created library into this directory I tried to compile Calculator.cpp using the following command:
$ g++ -o Calculator Calculator.cpp -L. -lMultiplier
which gives me these errors:
In file included from Calculator.cpp:1:
Calculator.h:1:24: error: Multiplier.h: No such file or directory
In file included from Calculator.cpp:1:
Calculator.h:6: error: ISO C++ forbids declaration of ‘Multiplier’ with no type
Calculator.h:6: error: expected ‘;’ before ‘&’ token
Calculator.h:8: error: expected `)' before ‘&’ token
Calculator.cpp:5: error: redefinition of ‘class something::Calculator’
Calculator.h:5: error: previous definition of ‘class something::Calculator’`
I have searched for a long time but can't work out what is happening. I am using GCC 4.2.1.
Your include file Multiplier.h is in another folder. How do you expect the compiler to find it? You need to tell the compiler where the file is, either using the -I command line flag and supplying the path of the include file, or using a path in the #include directive.