[][src]Macro postfix_macros::then

macro_rules! then {
    ($v:expr, $($body:tt)*) => { ... };

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);