# Function alloc::heap::deallocate [−] [src]

    pub unsafe fn deallocate(ptr: *mut u8, old_size: usize, align: usize)

Unstable (`heap_api` #27700)

: the precise API and guarantees it provides may be tweaked slightly, especially to possibly take into account the types being stored to make room for a future tracing garbage collector

Deallocates the memory referenced by `ptr`.

The `ptr` parameter must not be null.

The `old_size` and `align` parameters are the parameters that were used to create the allocation referenced by `ptr`. The `old_size` parameter may be any value in range_inclusive(requested_size, usable_size).

# Help

## Keyboard Shortcuts

?
  Show this help dialog
S
  Focus the search field
⇤
  Move up in search results
⇥
  Move down in search results
⏎
  Go to active search result

## Search Tricks

Prefix searches with a type followed by a colon (e.g. `fn:`) to restrict the search to a given type.

Accepted types are: `fn`, `mod`, `struct`, `enum`, `trait`, `type`, `macro`, and `const`.

Search functions by type signature (e.g. `vec -> usize`)