Compilare: user.cpp: In function ‘int read()’: user.cpp:22:16: warning: variable ‘semn’ set but not used [-Wunused-but-set-variable] int x = 0, semn = 1; ^ user.cpp: In function ‘char next()’: user.cpp:17:41: 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; ^