prog.cpp:2:16: error: default argument given for parameter 1 of 'int f(int)' [-fpermissive]
int f(int x = 0);
^
prog.cpp:1:5: note: previous specification in 'int f(int)' here
int f(int x = 0);
^
prog.cpp:3:16: error: default argument given for parameter 1 of 'int f(int)' [-fpermissive]
int f(int x = 0);
^
prog.cpp:2:5: note: previous specification in 'int f(int)' here
int f(int x = 0);
^