foo.cpp: In constructor 'bign::bign()':
foo.cpp:15:32: error: 'memset' was not declared in this scope
foo.cpp: In constructor 'bign::bign(char*)':
foo.cpp:17:19: error: 'strlen' was not declared in this scope
foo.cpp:19:24: error: 'memset' was not declared in this scope
foo.cpp: In function 'bign f(int)':
foo.cpp:109:11: warning: deprecated conversion from string constant to 'char*' [-Wwrite-strings]
foo.cpp: In function 'int main()':
foo.cpp:136:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]