macro_rules! then {
($v:expr, $($body:tt)*) => { ... };
}Expand description
Executes the body if the argument is true
Meant to be used in a postfix context, as
the postfix analog of if.
With the bool::then function, there is a
currently unstable
equivalent in the standard library, but
the macro doesn’t put the body into a
closure, and is thus more powerful.
Evaluates the first argument as a boolean,
and if it’s true, executes the body.
let mut w = 0;
for i in 1..10 {
w += i;
(w % i == 0).then!{ w += i * i };
}
assert_eq!(w, 75);