# Function alloc::alloc::alloc

1.28.0 · source ·

    pub unsafe fn alloc(layout: Layout) -> *mut u8

Expand description

Allocate memory with the global allocator.

This function forwards calls to the `GlobalAlloc::alloc` method of the allocator registered with the `#[global_allocator]` attribute if there is one, or the `std` crate’s default.

This function is expected to be deprecated in favor of the `alloc` method of the `Global` type when it and the `Allocator` trait become stable.

## Safety

See `GlobalAlloc::alloc`.

## Examples

    use std::alloc::{alloc, dealloc, handle_alloc_error, Layout};

    unsafe {
        let layout = Layout::new::<u16>();
        let ptr = alloc(layout);
        if ptr.is_null() {
            handle_alloc_error(layout);
        }

        *(ptr as *mut u16) = 42;
        assert_eq!(*(ptr as *mut u16), 42);

        dealloc(ptr, layout);
    }

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