This error occurs when an if
expression without an else
block is used in a context where a type other than ()
is expected, for example a let
expression:
fn main() { let x = 5; let a = if x == 5 { 1 }; }
An if
expression without an else
block has the type ()
, so this is a type error. To resolve it, add an else
block having the same type as the if
block.