How do I create a by-value iterator on the stack?

stack iterator java
java stack iterator reverse
stack iterator c++
iterate through stack python
java stack iterator implementation
java iterate stack backwards
stack hasnext
stack of integers

I can create a consuming iterator in the heap:

vec![1, 10, 100].into_iter()

I can also create an iterator on the stack that borrows the elements:

[1, 10, 100].iter()

But if I write this:

[1, 10, 100].into_iter()

This is not a consuming iterator because [T; _]::into_iter does not exist: IntoIterator is only implemented for the borrowed version (aka slice). Is there a simple way (preferably in the std lib) to create a consuming iterator on the stack?


I know that [1, 10, 100].iter().cloned() can be done, but this requires the items to be clonable.


You can have a macro which wraps the values in a once iterator and chains them together:

macro_rules! value_iter {
    () => {
        std::iter::empty()
    };
    ($v: expr, $( $rest: expr ), +) => {
        std::iter::once($v).chain(
            value_iter!($($rest),*)
        )
    };
    ($v: expr) => {
        std::iter::once($v)
    };
}

Using:

#[derive(Debug, PartialEq)]
struct Foo;

let it = value_iter![Foo, Foo, Foo];

let all: Vec<_> = it.collect();
assert_eq!(all, vec![Foo, Foo, Foo]);

A known drawback is that the iterator will not be an exact-size iterator, and so the compiler might miss some obvious optimizations.

Playground

Stack iterator() method in Java with Example, Return Value: The method iterates over the elements of the stack and returns the values(iterators). Creating an empty Stack + stack);. // Creating an iterator. Stack iterator() method in Java with Example The Java.util.Stack.iterator() method is used to return an iterator of the same elements as that of the Stack. The elements are returned in random order from what was present in the stack.


Is there a simple way (preferably in the std lib) to create a consuming iterator on the stack?

No.

Is there a simple way (preferably in the std lib) to create a consuming iterator on the stack?

Yes. Use a crate like stack or smallvec, which provide array types that implement IntoIterator.

Algorithms: Algorithms_4, Solution: The stack does not overflow unless there exists an integer k such that the When creating an iterator, store this value as an Iterator instance variable. Stack listIterator() method in Java with Example The listIterator() method of Java.util.Stack class is used to return a list iterator over the elements in this stack (in proper sequence). The returned list iterator is fail-fast.


Very ugly, but technically works:

for s in [
    Some(String::from("hello")),
    Some(String::from("goodbye"))
].iter_mut().map(|option| option.take().unwrap()) {
    let s: String = s;
    println!("{}", s);
}

You can use a macro that achieves this in a prettier way:

macro_rules! iter {
    [ $( $item:expr ),+ ] => {{
        [ $( Some($item), )+ ]
        .iter_mut()
        .map(|o| o.take().unwrap())
    }};
    // Rule to allow a trailing comma:
    [ $( $item:expr, )+ ] => {{
        iter![ $( $item ),+ ]
    }};
}

fn main() {
    for s in iter![String::from("hello"), String::from("goodbye")] {
        println!("{}", s);
    }
}

Does it make sense to iterate a ranged for loop using constant , Is it best to iterate using constant reference as I have done? Or would iterating by value be better (data_type temp: vec). I'm asking for both writing  Before we begin, we encourage you to read below post that points out a bug in Stack class that causes stack elements to be printed in FIFO order instead of expected LILO order. For example, iterator() method on java.util.Stack iterates through a stack in bottom-up manner.


The Advanced C++ Book, An important way of learning programming is by writing programs. for implementing stacks and sets, a cross reference generator, and an "iterator. class stack that has the following member functions: 1. push : add a float value to the stack. I'm trying to create some iterators for my class stack so that I can accomplish something like this when trying to loop through my stack: for (StackIterator<T> i = begin(); i != end(); ++i) where end is the 0th element of my stack (in an array), and begin is the element at the "top" of my stack (last element with info in array).


Do not claim that structs are on the stack · Issue #4561 · dotnet/docs , Value-type objects such as structs are created on the stack, while says unconditionally that ref struct locals are not allowed in iterators/async. Obtain an iterator to the start of the collection by calling the collection's iterator( ) method. Set up a loop that makes a call to hasNext( ). Have the loop iterate as long as hasNext( ) returns true. Within the loop, obtain each element by calling next( ). For collections that implement List, you can also obtain an iterator by calling ListIterator.


Iterate through collections in C#, Simple Iterator; Creating a Collection Class; Using Iterators with a Generic List This iteration returns a value of 5, and the current location in the iterator In the following example, the Stack<T> generic class implements the  I am using "Iterate Row Selection" in ModelBuilder to run through every line of a table. I am able to have the iterator create a rolling variable (Value), by selecting a field in "Group by Fields." If I "Group by Fields" on the field CNTRY_NAME, the iterator creates a value for that record on each iteration (i.e. Afghanistan). I can then plug