Compilare: user.cpp: In function ‘int read()’: user.cpp:19:21: warning: suggest parentheses around comparison in operand of ‘|’ [-Wparentheses] while(buffer[i] < 48 | buffer[i] > 57) ^ user.cpp:23:21: warning: suggest parentheses around comparison in operand of ‘&’ [-Wparentheses] while(buffer[i] > 47 & buffer[i] < 58) ^ user.cpp:21:65: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] if(++i == buffSize) fread(buffer, 1, buffSize, F), i = 0; ^ user.cpp:27:65: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] if(++i == buffSize) fread(buffer, 1, buffSize, F), i = 0; ^