Compilare: user.cpp: In function ‘bool Dijkstra()’: user.cpp:65:14: warning: statement has no effect [-Wunused-value] real_d[s]==0; ^ user.cpp: In member function ‘void myifstream::advance()’: user.cpp:57:43: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buffer,SIZE,1,input); ^ user.cpp: In constructor ‘myifstream::myifstream(const char*)’: user.cpp:25:39: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buffer,SIZE,1,input); ^