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.

shared void[] allocate(size_t);

Always returns null.

shared void[] alignedAllocate(size_t, uint);

Always returns null.

shared void[] allocateAll();

Always returns null.

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

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

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

These methods return false.

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

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

Returns Ternary.no.

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

Returns Ternary.no.

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

No-op.

Precondition b is null

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

No-op.

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

Returns Ternary.yes.

static shared NullAllocator instance;

Returns the shared global instance of the NullAllocator.