pipe.cpp: In function 'int main()': pipe.cpp:36: error: call of overloaded 'abs(int)' is ambiguous /usr/include/c++/4.4/cmath:94: note: candidates are: double std::abs(double) /usr/include/c++/4.4/cmath:98: note: float std::abs(float) /usr/include/c++/4.4/cmath:102: note: long double std::abs(long double) pipe.cpp:39: warning: comparison between signed and unsigned integer expressions pipe.cpp:54: error: call of overloaded 'abs(int)' is ambiguous /usr/include/c++/4.4/cmath:94: note: candidates are: double std::abs(double) /usr/include/c++/4.4/cmath:98: note: float std::abs(float) /usr/include/c++/4.4/cmath:102: note: long double std::abs(long double) pipe.cpp:55: error: 'memset' was not declared in this scope pipe.cpp:58: warning: comparison between signed and unsigned integer expressions