& (winter edition 🎄☃️❄️)
My favourite thing about C/C++:
Given foo(int x)
Did you know all of the following will decay into an int without a cast?
foo('a');foo(42);foo(3.5);foo(true);enum { a, b, c }; foo(a);
C++'s type promotion and decay rules are also such that
foo(double x)
Will accept both floats and doubles. Floats will be promoted to double automatically and silently. This isn't usually a problem, but I've had cases where I've had to be aware of which floating-point type is in use.
@Elizafox The cases where I can see is more in scientific simulations, where the difference between double and float could make algorithms non convergent.
Implicit conversions can be very dangerous. The Ariane 5 disaster happened because of a cast from 64-bit to 16-bit. Those are also implicit in C++ AFAIK.
https://en.wikipedia.org/wiki/Ariane_flight_V88#Launch_failure
@abde Generally speaking promotions are preferred to decay but if casted then all bets are off.
https://en.cppreference.com/w/c/language/conversion for minutiae about it