Hello Damian,
I agree with Lydia, this deserves an issue. Meanwhile here is some background.
We have decided to deprecate the interpretation of a real(?w) formal as stamping out one overload for real(32) and one for real(64). See this comment in #20011. So the warning you are observing is the compiler's way to say that. The warning was added in #22769.
I am more concerned that the compiler dispatches to the overload for (64, 64)-bit arguments. My expectation and probably your intention as well are to invoke the one for (32, 32). I could not tell why this happens upon a cursory look a the resolution rules in the spec .
The closest I got was this clause: "Discard any candidates that have more formals that require param narrowing conversions than another candidate." However it is unclear to me from the text whether the conversion of -270 to int(32) is "narrowing" or not. @mppf - any insights here?
Vass