implicit-declaration

Alternative of struct tm

Does there exist any other alternative data structure instead of struct tm (having same memory allocated as this structure) ? So that I could use strftime without declaring <time.h> I am aware of the fact that relying on implicit declaration is not good,but I faced this question in an interview. EDIT: To be precise I was asked to print...

Implicit declaration in C

Does the following program invoke Undefined Behaviour in C? int main() { printf("Printf asking: Where is my declaration ?"); } In the above program there is an implicit declaration of printf(), so is the above code fully standard compliant or it just has some implementation specific behaviour? ...