Struct RcBiConsumer 

pub struct RcBiConsumer<T, U> { /* private fields */ }

RcBiConsumer struct

A non-mutating bi-consumer implementation based on Rc<dyn Fn(&T, &U)> for single-threaded shared ownership scenarios. The wrapper does not need RefCell because it only invokes a shared Fn.

Features

• Shared Ownership: Cloneable via Rc, multiple owners allowed
• Single-Threaded: Not thread-safe, cannot send across threads
• No Wrapper Interior Mutability Overhead: No RefCell needed by the wrapper
• Non-Consuming API: and_then borrows &self, original remains usable

Use Cases

Choose RcBiConsumer when:

• Need to share non-mutating bi-consumer within a single thread
• Pure observation operations, performance critical
• Single-threaded UI framework event handling

Performance Advantages

RcBiConsumer has neither Arc’s atomic operation overhead nor RefCell’s runtime borrow checking overhead, making it the best performing among the three non-mutating bi-consumer types.

Examples

use qubit_function::{BiConsumer, RcBiConsumer};

let consumer: RcBiConsumer<i32, i32> = RcBiConsumer::new(|x: &i32, y: &i32| {
    println!("Sum: {}", x + y);
});
let clone = consumer.clone();

consumer.accept(&5, &3);
clone.accept(&10, &20);

Implementations

impl<T, U> RcBiConsumer<T, U>

pub fn new<F>(f: F) -> Self

where F: Fn(&T, &U) + 'static,

Creates a new bi-consumer.

Wraps the provided closure in the appropriate smart pointer type for this bi-consumer implementation.

Examples found in repository

examples/consumers/bi_consumer_observation_demo.rs (lines 83-86)

fn main() {
    println!("=== BiConsumer Observation Demo ===\n");

    // 1. BoxBiConsumer - Single ownership
    println!("1. BoxBiConsumer - Single ownership:");
    let box_consumer = BoxBiConsumer::new(|x: &i32, y: &i32| {
        println!("  Values: x={}, y={}, sum={}", x, y, x + y);
    });
    box_consumer.accept(&10, &5);
    println!();

    // 2. Method chaining with BoxBiConsumer
    println!("2. BoxBiConsumer with method chaining:");
    let chained = BoxBiConsumer::new(|x: &i32, y: &i32| {
        println!("  First operation: x={}, y={}", x, y);
    })
    .and_then(|x: &i32, y: &i32| {
        println!("  Second operation: sum={}", x + y);
    })
    .and_then(|x: &i32, y: &i32| {
        println!("  Third operation: product={}", x * y);
    });
    chained.accept(&5, &3);
    println!();

    // 3. ArcBiConsumer - Thread-safe shared ownership
    println!("3. ArcBiConsumer - Thread-safe shared ownership:");
    let counter = Arc::new(AtomicUsize::new(0));
    let c = counter.clone();
    let arc_consumer = ArcBiConsumer::new(move |x: &i32, y: &i32| {
        c.fetch_add(1, Ordering::SeqCst);
        println!("  Thread {:?}: sum={}", thread::current().id(), x + y);
    });

    let consumer1 = arc_consumer.clone();
    let consumer2 = arc_consumer.clone();

    let handle1 = thread::spawn(move || {
        consumer1.accept(&10, &5);
    });

    let handle2 = thread::spawn(move || {
        consumer2.accept(&20, &8);
    });

    handle1.join().expect("thread should not panic");
    handle2.join().expect("thread should not panic");
    println!("  Total calls: {}\n", counter.load(Ordering::SeqCst));

    // 4. RcBiConsumer - Single-threaded shared ownership
    println!("4. RcBiConsumer - Single-threaded shared ownership:");
    let counter = Rc::new(std::cell::Cell::new(0));
    let c = counter.clone();
    let rc_consumer = RcBiConsumer::new(move |x: &i32, y: &i32| {
        c.set(c.get() + 1);
        println!("  Call {}: sum={}", c.get(), x + y);
    });

    let clone1 = rc_consumer.clone();
    let clone2 = rc_consumer.clone();

    clone1.accept(&5, &3);
    clone2.accept(&7, &2);
    println!("  Total calls: {}\n", counter.get());

    // 5. Working with closures directly
    println!("5. Working with closures directly:");
    let closure = |x: &i32, y: &i32| {
        println!("  x={}, y={}, product={}", x, y, x * y);
    };
    closure.accept(&10, &20);
    println!();

    // 6. Pure observation - logging
    println!("6. Pure observation - logging:");
    let logger = BoxBiConsumer::new(|x: &i32, y: &i32| {
        println!("  [LOG] Processing pair: ({}, {})", x, y);
    });
    logger.accept(&5, &3);
    logger.accept(&10, &7);
    println!();

    // 7. Chaining observations
    println!("7. Chaining observations:");
    let log_input = BoxBiConsumer::new(|x: &i32, y: &i32| {
        println!("  [INPUT] x={}, y={}", x, y);
    });
    let log_sum = BoxBiConsumer::new(|x: &i32, y: &i32| {
        println!("  [SUM] {}", x + y);
    });
    let log_product = BoxBiConsumer::new(|x: &i32, y: &i32| {
        println!("  [PRODUCT] {}", x * y);
    });

    let chained = log_input.and_then(log_sum).and_then(log_product);
    chained.accept(&5, &3);
    println!();

    // 8. ArcBiConsumer - Reusability
    println!("8. ArcBiConsumer - Reusability:");
    let first = ArcBiConsumer::new(|x: &i32, y: &i32| {
        println!("  First: x={}, y={}", x, y);
    });
    let second = ArcBiConsumer::new(|x: &i32, y: &i32| {
        println!("  Second: sum={}", x + y);
    });

    // Both first and second can be reused after chaining
    let chained1 = first.and_then(second.clone());
    let chained2 = first.and_then(second.clone());

    println!("  Using chained1:");
    chained1.accept(&5, &3);

    println!("  Using chained2:");
    chained2.accept(&10, &2);
    println!();

    // 9. Name support
    println!("9. Name support:");
    let mut named_consumer = BoxBiConsumer::<i32, i32>::noop();
    println!("  Initial name: {:?}", named_consumer.name());

    named_consumer.set_name("sum_logger");
    println!("  After setting name: {:?}", named_consumer.name());
    println!("  Display: {}\n", named_consumer);

    // 10. No-op consumer
    println!("10. No-op consumer:");
    let noop = BoxBiConsumer::<i32, i32>::noop();
    noop.accept(&42, &10);
    println!("  No-op completed (no output expected)\n");

    println!("=== Demo Complete ===");
}

examples/consumers/bi_consumer_demo.rs (lines 109-111)

fn main() {
    println!("=== BiConsumer Demo ===\n");

    // 1. BoxBiConsumer - Single ownership
    println!("1. BoxBiConsumer - Single ownership:");
    let log = Arc::new(Mutex::new(Vec::new()));
    let l = log.clone();
    let box_consumer = BoxBiConsumer::new(move |x: &i32, y: &i32| {
        println!("  Processing: x={}, y={}", x, y);
        l.lock()
            .expect("mutex should not be poisoned")
            .push(*x + *y);
    });
    box_consumer.accept(&10, &5);
    println!(
        "  Result log: {:?}\n",
        *log.lock().expect("mutex should not be poisoned")
    );

    // 2. Method chaining with BoxBiConsumer
    println!("2. BoxBiConsumer with method chaining:");
    let log = Arc::new(Mutex::new(Vec::new()));
    let l1 = log.clone();
    let l2 = log.clone();
    let chained = BoxBiConsumer::new(move |x: &i32, y: &i32| {
        l1.lock()
            .expect("mutex should not be poisoned")
            .push(*x + *y);
        println!("  After first operation: sum = {}", x + y);
    })
    .and_then(move |x: &i32, y: &i32| {
        l2.lock()
            .expect("mutex should not be poisoned")
            .push(*x * *y);
        println!("  After second operation: product = {}", x * y);
    });
    chained.accept(&5, &3);
    println!(
        "  Final log: {:?}\n",
        *log.lock().expect("mutex should not be poisoned")
    );

    // 3. ArcBiConsumer - Thread-safe shared ownership
    println!("3. ArcBiConsumer - Thread-safe shared ownership:");
    let log = Arc::new(Mutex::new(Vec::new()));
    let l = log.clone();
    let arc_consumer = ArcBiConsumer::new(move |x: &i32, y: &i32| {
        l.lock()
            .expect("mutex should not be poisoned")
            .push(*x + *y);
        println!("  Thread {:?}: sum = {}", thread::current().id(), x + y);
    });

    let consumer1 = arc_consumer.clone();
    let consumer2 = arc_consumer.clone();

    let handle1 = thread::spawn(move || {
        let c = consumer1;
        c.accept(&10, &5);
    });

    let handle2 = thread::spawn(move || {
        let c = consumer2;
        c.accept(&20, &8);
    });

    handle1.join().expect("thread should not panic");
    handle2.join().expect("thread should not panic");
    println!(
        "  Final log: {:?}\n",
        *log.lock().expect("mutex should not be poisoned")
    );

    // 4. RcBiConsumer - Single-threaded shared ownership
    println!("4. RcBiConsumer - Single-threaded shared ownership:");
    let log = Rc::new(RefCell::new(Vec::new()));
    let l = log.clone();
    let rc_consumer = RcBiConsumer::new(move |x: &i32, y: &i32| {
        l.borrow_mut().push(*x + *y);
    });

    let clone1 = rc_consumer.clone();
    let clone2 = rc_consumer.clone();

    clone1.accept(&5, &3);
    println!("  After first use: {:?}", *log.borrow());

    clone2.accept(&7, &2);
    println!("  After second use: {:?}\n", *log.borrow());

    // 5. Working with closures directly
    println!("5. Working with closures directly:");
    let log = Arc::new(Mutex::new(Vec::new()));
    let l = log.clone();
    let closure = move |x: &i32, y: &i32| {
        let sum = *x + *y;
        l.lock().expect("mutex should not be poisoned").push(sum);
    };
    closure.accept(&10, &20);
    println!(
        "  After closure: {:?}\n",
        *log.lock().expect("mutex should not be poisoned")
    );

    // 6. Conditional BiConsumer
    println!("6. Conditional BiConsumer:");
    let log = Arc::new(Mutex::new(Vec::new()));
    let l = log.clone();
    let mut conditional = BoxStatefulBiConsumer::new(move |x: &i32, y: &i32| {
        l.lock()
            .expect("mutex should not be poisoned")
            .push(*x + *y);
    })
    .when(|x: &i32, y: &i32| *x > 0 && *y > 0);

    conditional.accept(&5, &3);
    println!(
        "  Positive values: {:?}",
        *log.lock().expect("mutex should not be poisoned")
    );

    conditional.accept(&-5, &3);
    println!(
        "  Negative value (unchanged): {:?}\n",
        *log.lock().expect("mutex should not be poisoned")
    );

    // 7. Conditional branch BiConsumer
    println!("7. Conditional branch BiConsumer:");
    let log = Arc::new(Mutex::new(Vec::new()));
    let l1 = log.clone();
    let l2 = log.clone();
    let mut branch = BoxStatefulBiConsumer::new(move |x: &i32, _y: &i32| {
        l1.lock().expect("mutex should not be poisoned").push(*x);
    })
    .when(|x: &i32, y: &i32| *x > *y)
    .or_else(move |_x: &i32, y: &i32| {
        l2.lock().expect("mutex should not be poisoned").push(*y);
    });

    branch.accept(&15, &10);
    println!(
        "  When x > y: {:?}",
        *log.lock().expect("mutex should not be poisoned")
    );

    branch.accept(&5, &10);
    println!(
        "  When x <= y: {:?}\n",
        *log.lock().expect("mutex should not be poisoned")
    );

    // 8. Accumulating statistics
    println!("8. Accumulating statistics:");
    let count = Arc::new(Mutex::new(0));
    let sum = Arc::new(Mutex::new(0));
    let c = count.clone();
    let s = sum.clone();
    let stats_consumer = BoxBiConsumer::new(move |x: &i32, y: &i32| {
        *c.lock().expect("mutex should not be poisoned") += 1;
        *s.lock().expect("mutex should not be poisoned") += x + y;
    });

    stats_consumer.accept(&5, &3);
    stats_consumer.accept(&10, &2);
    stats_consumer.accept(&7, &8);

    println!(
        "  Count: {}",
        *count.lock().expect("mutex should not be poisoned")
    );
    println!(
        "  Sum: {}\n",
        *sum.lock().expect("mutex should not be poisoned")
    );

    // 9. Name support
    println!("9. Name support:");
    let mut named_consumer = BoxBiConsumer::<i32, i32>::noop();
    println!("  Initial name: {:?}", named_consumer.name());

    named_consumer.set_name("sum_calculator");
    println!("  After setting name: {:?}", named_consumer.name());
    println!("  Display: {}\n", named_consumer);

    println!("=== Demo Complete ===");
}

pub fn new_with_name<F>(name: &str, f: F) -> Self

where F: Fn(&T, &U) + 'static,

Creates a new named bi-consumer.

Wraps the provided closure and assigns it a name, which is useful for debugging and logging purposes.

pub fn new_with_optional_name<F>(f: F, name: Option<String>) -> Self

where F: Fn(&T, &U) + 'static,

Creates a new named bi-consumer with an optional name.

Wraps the provided closure and assigns it an optional name.

pub fn name(&self) -> Option<&str>

Gets the name of this bi-consumer.

Returns

Returns Some(&str) if a name was set, None otherwise.

pub fn set_name(&mut self, name: &str)

Sets the name of this bi-consumer.

Parameters

• name - The name to set for this bi-consumer

pub fn clear_name(&mut self)

Clears the name of this bi-consumer.

pub fn noop() -> Self

Creates a no-operation bi-consumer.

Creates a bi-consumer that does nothing when called. Useful for default values or placeholder implementations.

Returns

Returns a new bi-consumer instance that performs no operation.

pub fn when<P>(&self, predicate: P) -> RcConditionalBiConsumer<T, U>

where T: 'static, U: 'static, P: BiPredicate<T, U> + 'static,

Creates a conditional bi-consumer

Wraps this bi-consumer with a bi-predicate condition, creating a new conditional bi-consumer that will only execute the original bi-consumer when the predicate evaluates to true.

Parameters

• predicate - The condition that must be satisfied for the bi-consumer to execute

Returns

Returns a conditional bi-consumer that executes this bi-consumer only when the predicate is satisfied

Examples

use qubit_function::{ArcBiConsumer, BiConsumer};
let consumer = ArcBiConsumer::new(|x: &i32, y: &i32| println!("{}", x + y));
let conditional = consumer.when(|x: &i32, y: &i32| *x > 0 && *y > 0);

conditional.accept(&5, &3);  // prints: 8
conditional.accept(&-5, &3); // prints nothing

pub fn and_then<C>(&self, after: C) -> RcBiConsumer<T, U>

where T: 'static, U: 'static, C: BiConsumer<T, U> + 'static,

Chains another bi-consumer in sequence

Combines this bi-consumer with another bi-consumer into a new bi-consumer that executes both bi-consumers in sequence. The returned bi-consumer first executes this bi-consumer, then unconditionally executes the after bi-consumer.

Parameters

• after - The bi-consumer to execute after this one (always executed)

Returns

Returns a new bi-consumer that executes both bi-consumers in sequence

Examples

use qubit_function::{ArcBiConsumer, BiConsumer};
let consumer1 = ArcBiConsumer::new(|x: &i32, y: &i32| print!("first: {}", x + y));
let consumer2 = ArcBiConsumer::new(|x: &i32, y: &i32| println!(" second: {}", x * y));

let chained = consumer1.and_then(consumer2);

chained.accept(&5, &3);  // prints: first: 8 second: 15

Trait Implementations

impl<T, U> BiConsumer<T, U> for RcBiConsumer<T, U>

fn accept(&self, first: &T, second: &U)

Performs the non-mutating consumption operation

fn into_box(self) -> BoxBiConsumer<T, U>

where Self: 'static,

Converts to BoxBiConsumer

fn into_rc(self) -> RcBiConsumer<T, U>

Converts to RcBiConsumer

fn into_fn(self) -> impl Fn(&T, &U)

Converts non-mutating bi-consumer to a closure

fn to_box(&self) -> BoxBiConsumer<T, U>

where Self: 'static,

Converts to BoxBiConsumer (without consuming self)

fn to_rc(&self) -> RcBiConsumer<T, U>

Converts to RcBiConsumer (without consuming self)

fn to_fn(&self) -> impl Fn(&T, &U)

Converts to a closure (without consuming self)

fn into_once(self) -> BoxBiConsumerOnce<T, U>

where Self: 'static,

Convert to BiConsumerOnce

fn to_once(&self) -> BoxBiConsumerOnce<T, U>

where Self: 'static,

Convert to BiConsumerOnce without consuming self

fn into_arc(self) -> ArcBiConsumer<T, U>

where Self: Sized + Send + Sync + 'static,

Converts to ArcBiConsumer

fn to_arc(&self) -> ArcBiConsumer<T, U>

where Self: Clone + Send + Sync + 'static,

Converts to ArcBiConsumer (without consuming self)

impl<T, U> Clone for RcBiConsumer<T, U>

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T, U> Debug for RcBiConsumer<T, U>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<T, U> Display for RcBiConsumer<T, U>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.