C# Programming/Keywords/stackalloc

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The keyword stackalloc is used in an unsafe code context to allocate a block of memory on the stack.

int* fib = stackalloc int[100];

In the example above, a block of memory of sufficient size to contain 100 elements of type int is allocated on the stack, not the heap; the address of the block is stored in the pointer fib. This memory is not subject to garbage collection and therefore does not have to be pinned (via fixed). The lifetime of the memory block is limited to the lifetime of the method in which it is defined (there is no way to free the memory before the method returns).

stackalloc is only valid in local variable initializers.

Because Pointer types are involved, stackalloc requires unsafe context. See Unsafe Code and Pointers.

stackalloc is similar to _alloca in the C run-time library.

Note* - From MSDN

C# Keywords
abstract as base bool break
byte case catch char checked
class const continue decimal default
delegate do double else enum
event explicit extern false finally
fixed float for foreach
goto if implicit in int
interface internal is lock long
namespace new null object operator
out override params private protected
public readonly ref return sbyte
sealed short sizeof stackalloc
static string struct switch this
throw true try typeof uint
ulong unchecked unsafe ushort using
var virtual void volatile while
Special C# Identifiers
add alias get global partial
remove set value where yield