Possible bug in the borrow checker

[Neutron3529]

Unfortunately, It is not a bug.

It is documented..

[Pre-Pre-RFC] Yet another discussion of if-let and while-let lifetime

This might be a breaking change, although it may not affect too much code. There is always someone talking about the question that if-let and while-let lives too long. If we focus on if clause and if-let clause, a much strange things could happen: // Works if x.borrow().is_negative(){ *x.borrow_mut() = 0 }else{*x.borrow_mut() = 0} // Panics if let false=x.borrow().is_negative(){ *x.borrow_mut() = 0 }else{*x.borrow_mut() = 0} It seems that, temporary variables' drop times shou…

give some useful discussion (not my post, but someone who against me shows lots of really useful reasons.)