std.experimental.allocator.building_blocks.null_allocator

struct NullAllocator;

NullAllocator is an emphatically empty implementation of the allocator interface. Although it has no direct use, it is useful as a "terminator" in composite allocators.

enum uint alignment;

NullAllocator advertises a relatively large alignment equal to 64 KB. This is because NullAllocator never actually needs to honor this alignment and because composite allocators using NullAllocator shouldn't be unnecessarily constrained.

pure nothrow @nogc @safe void[] allocate(size_t) shared;

Always returns null.

pure nothrow @nogc @safe void[] alignedAllocate(size_t, uint) shared;

Always returns null.

pure nothrow @nogc @safe void[] allocateAll() shared;

Always returns null.

pure nothrow @nogc @safe bool expand(ref void[] b, size_t s) shared;

pure nothrow @nogc @safe bool reallocate(ref void[] b, size_t) shared;

pure nothrow @nogc @safe bool alignedReallocate(ref void[] b, size_t, uint) shared;

These methods return false.

Precondition b is null. This is because there is no other possible legitimate input.

pure nothrow @nogc @safe Ternary owns(const void[]) shared const;

Returns Ternary.no.

pure nothrow @nogc @safe Ternary resolveInternalPointer(const void*, ref void[]) shared const;

Returns Ternary.no.

pure nothrow @nogc @safe bool deallocate(void[] b) shared;

No-op.

Precondition b is null

pure nothrow @nogc @safe bool deallocateAll() shared;

No-op.

pure nothrow @nogc @safe Ternary empty() shared const;

Returns Ternary.yes.

static shared NullAllocator instance;

Returns the shared global instance of the NullAllocator.