Compilare: user.cpp: In function ‘int union1(int, int)’: user.cpp:51:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In function ‘char next()’: user.cpp:15:41: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buf, 1, BUF, fin), pos = 0; ^