Make Install Failed: by error unused function readData

[voidabhi]

Command

$ make && sudo make install

Environment

OSX Yosemite 10.10.2
GNU Make 3.81
gxx version 6.1.0 

Output

Making all in src
Making all in utilspp
make[2]: Nothing to be done for `all'.
Making all in curlpp
Making all in internal
make[3]: Nothing to be done for `all'.
make[3]: Nothing to be done for `all-am'.
make[2]: Nothing to be done for `all-am'.
Making all in include
Making all in curlpp
/Applications/Xcode.app/Contents/Developer/usr/bin/make  all-recursive
Making all in internal
make[4]: Nothing to be done for `all'.
make[4]: Nothing to be done for `all-am'.
Making all in utilspp
Making all in functor
make[3]: Nothing to be done for `all'.
Making all in singleton
make[3]: Nothing to be done for `all'.
make[3]: Nothing to be done for `all-am'.
make[2]: Nothing to be done for `all-am'.
Making all in examples
g++ -DHAVE_CONFIG_H -I. -I../include/curlpp -I../include    -g  -W -Wall -Werror    -I/usr/local/include -MT example21.o -MD -MP -MF .deps/example21.Tpo -c -o example21.o example21.cpp
example21.cpp:51:8: error: unused function 'readData'
      [-Werror,-Wunused-function]
size_t readData(char *buffer, size_t size, size_t nitems)
       ^
1 error generated.
make[1]: *** [example21.o] Error 1
make: *** [all-recursive] Error 1

[vicaba]

I get this error too. The solution was to comment the problematic code