Compilare: user.cpp: In function ‘std::string clear(std::string&)’: user.cpp:25:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (val.find('"', 0) != -1) { ^ user.cpp:32:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (val.find('?', 0) != -1) { ^ user.cpp:36:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (val.find('}', 0) != -1) { ^ user.cpp: In function ‘void convert()’: user.cpp:70:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (slot.find("}") == -1) { ^ user.cpp: In function ‘int main()’: user.cpp:101:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("convertor.in", "r", stdin); ^ user.cpp:102:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("convertor.out", "w+", stdout); ^