Trait InTrue 

pub trait InTrue: Sized {
    // Required methods
    fn in_true<F, R>(&mut self, f: F) -> Option<R>
       where F: FnOnce() -> R;
    fn in_false<F, R>(&mut self, f: F) -> Option<R>
       where F: FnOnce() -> R;
}

let mut state = false;
let mut n = 0;

assert_eq!(state.in_true(|| n += 1), None);
assert_eq!((n, state), (0, true));

assert_eq!(state.in_true(|| n += 1), Some(()));
assert_eq!((n, state), (1, true));

assert_eq!(state.in_false(|| n += 1), None);
assert_eq!((n, state), (1, false));

assert_eq!(state.in_false(|| n += 1), Some(()));
assert_eq!((n, state), (2, false));

Required Methods

fn in_true<F, R>(&mut self, f: F) -> Option<R>

where F: FnOnce() -> R,

Run f when *self == true, then assign *self to true

fn in_false<F, R>(&mut self, f: F) -> Option<R>

where F: FnOnce() -> R,

Run f when *self == false, then assign *self to false

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementations on Foreign Types

impl InTrue for bool

fn in_true<F, R>(&mut self, f: F) -> Option<R>

where F: FnOnce() -> R,

fn in_false<F, R>(&mut self, f: F) -> Option<R>

where F: FnOnce() -> R,

Implementors