Macro into_heap 

macro_rules! into_heap {
    (
  $( $key: expr ),* $( , )?
 ) => { ... };
}

Creates a BinaryHeap from a list of elements.

The into_heap macro simplifies the creation of a BinaryHeap with initial elements. Elements passed to the macro are automatically converted into the heap’s element type using .into(), allowing for the use of literals or values of different, but convertible types.

Note: The into_heap macro utilizes the .into() method to convert each element into the target type of the BinaryHeap. This means that the elements must be compatible with the Into< T > trait for the type T used in the BinaryHeap. Also, this means that sometimes you must specify the type of collection’s items.

Origin

This collection is reexported from alloc.

Syntax

The macro can be called with a comma-separated list of elements. A trailing comma is optional.

// BinaryHeap of i32
let heap1: BinaryHeap< i32 > = into_heap!( 3, 1, 4, 1, 5, 9 );

// BinaryHeap of String
let heap2: BinaryHeap< String > = into_heap!{ "pear".to_string(), "apple", "banana" };

// With trailing comma
let heap3: BinaryHeap< i32 > = into_heap!( 2, 7, 1, 8, );

Parameters

• $( $key: expr ),* $( , )? : A comma-separated list of elements to insert into the BinaryHeap. Each element can be of any type that implements the Into< T > trait, where T is the type stored in the BinaryHeap.

Returns

Returns a BinaryHeap containing all the specified elements. The capacity of the heap is automatically determined based on the number of elements provided.

Example

Basic usage with integers :

let heap: BinaryHeap< i32 > = into_heap!( 5, 3, 7, 1 );
assert_eq!( heap.peek(), Some( &7 ) ); // The largest value is at the top of the heap

Example

Using with different types that implement Into< T > :

let chars: BinaryHeap< char > = into_heap!( 'a', 'b', 'c' );
assert_eq!( chars.peek(), Some( &'c' ) ); // Characters are ordered by their ASCII value

Example

Creating a BinaryHeap of String from string literals :

let fruits: BinaryHeap< String > = into_heap!{ "cherry", "apple", "banana" };
assert_eq!( fruits.peek(), Some( &"cherry".to_string() ) ); // The lexicographically largest value is at the top