diff --git a/lib/std/core/allocators/memory_arena.c3 b/lib/std/core/allocators/arena_allocator.c3
similarity index 66%
rename from lib/std/core/allocators/memory_arena.c3
rename to lib/std/core/allocators/arena_allocator.c3
index f8ae57688..c67cab95b 100644
--- a/lib/std/core/allocators/memory_arena.c3
+++ b/lib/std/core/allocators/arena_allocator.c3
@@ -6,7 +6,7 @@ module std::core::mem::allocator;
  */
 private fn void*! arena_allocator_function(Allocator* data, usize size, usize alignment, void* old_pointer, AllocationKind kind)
 {
-	MemoryArena* arena = (MemoryArena*)data;
+	ArenaAllocator* arena = (ArenaAllocator*)data;
 	switch (kind)
 	{
 		case CALLOC:
@@ -16,18 +16,18 @@ private fn void*! arena_allocator_function(Allocator* data, usize size, usize al
 			alignment = alignment_for_allocation(alignment);
 			void* mem = arena.alloc(size, alignment, DEFAULT_SIZE_PREFIX)?;
 			*(usize*)(mem - DEFAULT_SIZE_PREFIX) = size;
-			if (kind == AllocationKind.CALLOC) mem::set(mem, 0, size);
+			if (kind == AllocationKind.CALLOC) mem::memset(mem, 0, size, false, DEFAULT_MEM_ALIGNMENT);
         	return mem;
 		case REALLOC:
 			if (!size) nextcase FREE;
 			if (!old_pointer) nextcase ALLOC;
-			assert((uptr)old_pointer >= (uptr)arena.memory, "Pointer originates from a different allocator.");
-			if (size > arena.total) return AllocationFailure.OUT_OF_MEMORY!;
+			assert((uptr)old_pointer >= (uptr)arena.data.ptr, "Pointer originates from a different allocator.");
+			if (size > arena.data.len) return AllocationFailure.CHUNK_TOO_LARGE!;
 			alignment = alignment_for_allocation(alignment);
 			usize* old_size_ptr = (usize*)(old_pointer - DEFAULT_SIZE_PREFIX);
 			usize old_size = *old_size_ptr;
 			// Do last allocation and alignment match?
-			if (arena.memory + arena.used  == old_pointer + old_size && mem::ptr_is_aligned(old_pointer, alignment))
+			if (&arena.data[arena.used]  == old_pointer + old_size && mem::ptr_is_aligned(old_pointer, alignment))
 			{
 				if (old_size >= size)
 				{
@@ -36,7 +36,7 @@ private fn void*! arena_allocator_function(Allocator* data, usize size, usize al
 					return old_pointer;
 				}
 				usize new_used = arena.used + size - old_size;
-				if (new_used > arena.total) return AllocationFailure.OUT_OF_MEMORY!;
+				if (new_used > arena.data.len) return AllocationFailure.OUT_OF_MEMORY!;
 				arena.used = new_used;
 				*old_size_ptr = size;
 				return old_pointer;
@@ -44,19 +44,21 @@ private fn void*! arena_allocator_function(Allocator* data, usize size, usize al
 			// Otherwise just allocate new memory.
 			void* mem = arena.alloc(size, alignment, DEFAULT_SIZE_PREFIX)?;
 			*(usize*)(mem - DEFAULT_SIZE_PREFIX) = size;
-			mem::copy(mem, old_pointer, old_size);
+			mem::memcpy(mem, old_pointer, old_size, false, DEFAULT_MEM_ALIGNMENT, DEFAULT_MEM_ALIGNMENT);
 			return mem;
 		case FREE:
 			if (!old_pointer) return null;
-			assert((uptr)old_pointer >= (uptr)arena.memory, "Pointer originates from a different allocator.");
+			assert((uptr)old_pointer >= (uptr)arena.data.ptr, "Pointer originates from a different allocator.");
 			usize old_size = *(usize*)(old_pointer - DEFAULT_SIZE_PREFIX);
-			if (old_pointer + old_size == arena.memory + arena.used)
+			if (old_pointer + old_size == &arena.data[arena.used])
         	{
         		arena.used -= old_size;
         	}
         	return null;
+        case MARK:
+            return (void*)(uptr)arena.used;
 		case RESET:
-			arena.used = 0;
+			arena.used = size;
 			return null;
 	}
 	unreachable();
@@ -69,14 +71,14 @@ private fn void*! arena_allocator_function(Allocator* data, usize size, usize al
  * @require alignment <= MAX_MEMORY_ALIGNMENT `alignment too big`
  * @require this != null
  **/
-private fn void*! MemoryArena.alloc(MemoryArena* this, usize size, usize alignment, usize prefixed_bytes = 0)
+private fn void*! ArenaAllocator.alloc(ArenaAllocator* this, usize size, usize alignment, usize prefixed_bytes = 0)
 {
-	void* start_mem = this.memory;
+	void* start_mem = this.data.ptr;
 	void* unaligned_pointer = start_mem + this.used + prefixed_bytes;
 	if ((uptr)unaligned_pointer < (uptr)start_mem) return AllocationFailure.OUT_OF_MEMORY!;
 	usize offset_start = mem::aligned_offset((usize)(uptr)unaligned_pointer, alignment) - (usize)(uptr)start_mem;
 	usize end = offset_start + size;
-	if (end > this.total || end < offset_start) return AllocationFailure.OUT_OF_MEMORY!;
+	if (end > this.data.len || end < offset_start) return AllocationFailure.OUT_OF_MEMORY!;
 	this.used = end;
 	return start_mem + offset_start;
 }
\ No newline at end of file
diff --git a/lib/std/core/allocators/dynamic_arena.c3 b/lib/std/core/allocators/dynamic_arena.c3
index 65305197e..bea600662 100644
--- a/lib/std/core/allocators/dynamic_arena.c3
+++ b/lib/std/core/allocators/dynamic_arena.c3
@@ -54,7 +54,7 @@ private fn void*! DynamicArenaAllocator.realloc(DynamicArenaAllocator* this, voi
 		return old_pointer;
 	}
 	void* new_mem = this.alloc(size, alignment)?;
-	mem::copy(new_mem, old_pointer, old_size);
+	mem::memcpy(new_mem, old_pointer, old_size, false, DEFAULT_MEM_ALIGNMENT);
 	return new_mem;
 }
 
@@ -154,7 +154,7 @@ private fn void*! dynamic_arena_allocator_function(Allocator* data, usize size,
 			assert(!old_pointer, "Unexpected no old pointer for calloc.");
 			if (!size) return null;
 			void* mem = allocator.alloc(size, alignment)?;
-			mem::set(mem, 0, size);
+			mem::memset(mem, 0, size, false, DEFAULT_MEM_ALIGNMENT);
 			return mem;
 		case ALLOC:
 			assert(!old_pointer, "Unexpected no old pointer for alloc.");
@@ -174,6 +174,8 @@ private fn void*! dynamic_arena_allocator_function(Allocator* data, usize size,
 			if (!old_pointer) return null;
 			allocator.free(old_pointer);
 			return null;
+		case MARK:
+			unreachable("Tried to mark a dynamic arena");
 		case RESET:
 			allocator.reset();
 			return null;
diff --git a/lib/std/core/allocators/mem_allocator_fn.c3 b/lib/std/core/allocators/mem_allocator_fn.c3
index 0aeb59f69..f9ac1749a 100644
--- a/lib/std/core/allocators/mem_allocator_fn.c3
+++ b/lib/std/core/allocators/mem_allocator_fn.c3
@@ -28,7 +28,8 @@ fn void*! libc_allocator_fn(Allocator* unused, usize bytes, usize alignment, voi
         case ALLOC:
             if (alignment > DEFAULT_MEM_ALIGNMENT)
             {
-	            data = (void*)mem::aligned_offset((iptr)libc::malloc(bytes + alignment), alignment);
+                if (alignment > bytes) bytes = alignment;
+	            data = libc::aligned_alloc(alignment, bytes);
             }
             else
             {
@@ -39,23 +40,36 @@ fn void*! libc_allocator_fn(Allocator* unused, usize bytes, usize alignment, voi
         case CALLOC:
             if (alignment > DEFAULT_MEM_ALIGNMENT)
             {
-	            data = (void*)mem::aligned_offset((iptr)libc::calloc(bytes + alignment, 1), alignment);
+                if (alignment > bytes) bytes = alignment;
+                data = libc::aligned_alloc(bytes, alignment);
+                mem::memset(data, 0, bytes, false, DEFAULT_MEM_ALIGNMENT);
             }
             else
             {
-                data = libc::malloc(bytes);
+                data = libc::calloc(bytes, 1);
             }
             if (!data) return AllocationFailure.OUT_OF_MEMORY!;
             return data;
         case REALLOC:
-            if (alignment > DEFAULT_MEM_ALIGNMENT)
-            {
-	            data = (void*)mem::aligned_offset((iptr)libc::realloc(old_pointer, bytes + alignment), alignment);
-            }
-            else
-            {
-                data = libc::realloc(old_pointer, bytes);
-            }
+            if (!bytes) nextcase FREE;
+            if (!old_pointer) nextcase CALLOC;
+            $if (libc::HAS_MALLOC_SIZE):
+	            if (alignment > DEFAULT_MEM_ALIGNMENT)
+                {
+                    usize size = libc::malloc_size(old_pointer);
+                if (alignment > bytes) bytes = alignment;
+	                data = libc::aligned_alloc(bytes, alignment);
+		            if (!data) return AllocationFailure.OUT_OF_MEMORY!;
+	                if (bytes > size)
+	                {
+	                    mem::memset(data + size, 0, bytes - size, false, DEFAULT_MEM_ALIGNMENT);
+	                }
+                    mem::memcpy(data, old_pointer, size, false, DEFAULT_MEM_ALIGNMENT, DEFAULT_MEM_ALIGNMENT);
+                    libc::free(old_pointer);
+                    return data;
+                }
+            $endif;
+            data = libc::realloc(old_pointer, bytes);
             if (!data) return AllocationFailure.OUT_OF_MEMORY!;
             return data;
         case RESET:
diff --git a/lib/std/core/allocators/temp_allocator.c3 b/lib/std/core/allocators/temp_allocator.c3
new file mode 100644
index 000000000..749970a11
--- /dev/null
+++ b/lib/std/core/allocators/temp_allocator.c3
@@ -0,0 +1,197 @@
+module std::core::mem::allocator;
+import std::io;
+
+private struct TempAllocatorChunk
+{
+	usize size;
+	char[*] data;
+}
+
+struct TempAllocator
+{
+	inline Allocator allocator;
+	Allocator* backing_allocator;
+	TempAllocatorPage* last_page;
+	usize used;
+	usize capacity;
+	char[*] data;
+}
+
+struct TempAllocatorPage
+{
+	TempAllocatorPage* prev_page;
+	usize mark;
+	void* start;
+	usize size;
+	usize ident;
+	char[*] data;
+}
+
+/**
+ * @require size >= 16
+ **/
+fn TempAllocator*! new_temp(usize size, Allocator* backing_allocator)
+{
+	TempAllocator* allocator = backing_allocator.alloc(size + TempAllocator.sizeof)?;
+	allocator.last_page = null;
+	allocator.function = &temp_allocator_function;
+	allocator.backing_allocator = backing_allocator;
+	allocator.used = 0;
+	allocator.capacity = size;
+	return allocator;
+}
+
+/**
+ * @require !alignment || math::is_power_of_2(alignment)
+ * @require data `unexpectedly missing the allocator`
+ */
+private fn void*! temp_allocator_function(Allocator* data, usize size, usize alignment, void* old_pointer, AllocationKind kind)
+{
+	TempAllocator* arena = (TempAllocator*)data;
+	switch (kind)
+	{
+		case CALLOC:
+		case ALLOC:
+			assert(!old_pointer, "Unexpected old pointer for alloc.");
+			if (!size) return null;
+			return arena._alloc(size, alignment_for_allocation(alignment), kind == AllocationKind.CALLOC);
+		case REALLOC:
+			if (!size) nextcase FREE;
+			if (!old_pointer) nextcase ALLOC;
+			return arena._realloc(old_pointer, size, alignment_for_allocation(alignment));
+		case FREE:
+			if (!old_pointer) return null;
+			assert((uptr)old_pointer >= (uptr)&arena.data, "Pointer originates from a different allocator.");
+			usize old_size = *(usize*)(old_pointer - DEFAULT_SIZE_PREFIX);
+			if (old_pointer + old_size == &arena.data[arena.used])
+        	{
+        		arena.used -= old_size;
+        	}
+        	return null;
+        case MARK:
+            return (void*)(uptr)arena.used;
+		case RESET:
+			arena._reset(size)?;
+			return null;
+	}
+	unreachable();
+}
+
+
+private fn void! TempAllocator._reset(TempAllocator* this, usize mark)
+{
+	TempAllocatorPage *last_page = this.last_page;
+	while (last_page)
+	{
+		if (last_page.mark < mark) break;
+		void* mem = last_page.start;
+		last_page = last_page.prev_page;
+		this.backing_allocator.free(mem)?;
+	}
+	this.last_page = last_page;
+	this.used = mark;
+}
+
+private fn void*! TempAllocator._realloc(TempAllocator* this, void* pointer, usize size, usize alignment)
+{
+	TempAllocatorChunk *chunk = pointer - TempAllocatorChunk.sizeof;
+	if (chunk.size == ~(usize)0)
+	{
+		assert(this.last_page, "Realloc of non temp pointer");
+		// First grab the page
+		TempAllocatorPage *page = pointer - TempAllocatorPage.sizeof;
+
+		// Then the actual start pointer:
+		void* real_pointer = page.start;
+
+		// Walk backwards to find the pointer to this page.
+		TempAllocatorPage **pointer_to_prev = &this.last_page;
+
+		// Remove the page from the list
+		while (*pointer_to_prev != page)
+		{
+			pointer_to_prev = &((*pointer_to_prev).prev_page);
+		}
+		*pointer_to_prev = page.prev_page;
+
+		// Find the new header size
+		usize actual_header_size = mem::aligned_offset(TempAllocatorPage.sizeof, alignment);
+		// And the old one.
+		uptrdiff prev_header_size = pointer - real_pointer;
+
+		// If the new header size needs to move, we're out of luck.
+		// We need to make a copy
+		if (actual_header_size > prev_header_size)
+		{
+			// Clear only if the new size is bigger than the old one.
+			void* data = this._alloc(size, alignment, size > page.size)?;
+			mem::memcpy(data, pointer, page.size);
+			this.backing_allocator.free(real_pointer)?;
+			return data;
+		}
+		void* new_start = this.backing_allocator.realloc(real_pointer, prev_header_size + size, alignment)?;
+		page = new_start + prev_header_size - TempAllocatorPage.sizeof;
+		page.mark = this.used;
+		page.prev_page = this.last_page;
+		this.last_page = page;
+		io::printf("Size: %d\n", size);
+		page.size = size;
+		page.start = new_start;
+		return &page.data;
+	}
+	assert(pointer < &this.data + this.capacity && pointer >= &this.data, "This is not a temp allocated pointer.");
+	assert(pointer < &this.data + this.used, "This is a stale temp pointer.");
+
+	io::printf("realloc normal %s\n", size);
+	// TODO optimize last allocation
+	TempAllocatorChunk* data = this._alloc(size, alignment, size > chunk.size)?;
+	mem::memcpy(data, pointer, chunk.size, false, DEFAULT_MEM_ALIGNMENT, DEFAULT_MEM_ALIGNMENT);
+
+	return data;
+}
+
+/**
+ * @require alignment > 0 `alignment must be non zero`
+ * @require math::is_power_of_2(alignment)
+ * @require size > 0
+ * @require alignment <= MAX_MEMORY_ALIGNMENT `alignment too big`
+ * @require this != null
+ **/
+private fn void*! TempAllocator._alloc(TempAllocator* this, usize size, usize alignment, bool clear)
+{
+	void* start_mem = &this.data;
+	uptr starting_ptr = (uptr)start_mem + this.used;
+	uptr aligned_header_start = mem::aligned_offset(starting_ptr, $alignof(TempAllocatorChunk));
+	uptr unaligned_data_start = aligned_header_start + TempAllocatorChunk.sizeof;
+	usize data_start = mem::aligned_offset(unaligned_data_start, alignment);
+
+	usize new_usage = data_start + size - (uptr)start_mem;
+
+	// Fallback to backing allocator
+	if (new_usage > this.capacity)
+	{
+		// Enlarge the header if needed
+		usize actual_header_size = mem::aligned_offset(TempAllocator.sizeof, alignment);
+		usize total_alloc_size = actual_header_size + size;
+		void* start = clear ? this.backing_allocator.calloc(total_alloc_size, alignment) : this.backing_allocator.alloc(total_alloc_size, alignment)?;
+
+		// Move forward to the memory
+		void* mem = start + actual_header_size;
+		TempAllocatorPage* page = mem - TempAllocator.sizeof;
+		page.start = start;
+		page.ident = ~(usize)0;
+		page.mark = this.used;
+		page.size = size;
+		page.prev_page = this.last_page;
+		this.last_page = page;
+		assert(&page.data == mem, "Expected match");
+		return mem;
+	}
+
+	TempAllocatorChunk* chunk_start = (TempAllocatorChunk*)(data_start - TempAllocatorChunk.sizeof);
+	chunk_start.size = size;
+	this.used = new_usage;
+	void* mem = &chunk_start.data;
+	if (clear) mem::memset(mem, 0, size, false, DEFAULT_MEM_ALIGNMENT);
+	return mem;
+}
\ No newline at end of file
diff --git a/lib/std/core/env.c3 b/lib/std/core/env.c3
index 5c675069a..e24f04a8c 100644
--- a/lib/std/core/env.c3
+++ b/lib/std/core/env.c3
@@ -56,3 +56,4 @@ const CompilerOptLevel COMPILER_OPT_LEVEL = (CompilerOptLevel)($$COMPILER_OPT_LE
 const bool BIG_ENDIAN = $$PLATFORM_BIG_ENDIAN;
 const bool I128_SUPPORT = $$PLATFORM_I128_SUPPORTED;
 const bool COMPILER_SAFE_MODE = $$COMPILER_SAFE_MODE;
+const usize TEMP_ALLOCATOR_SIZE = 128 * 1024;
\ No newline at end of file
diff --git a/lib/std/core/mem.c3 b/lib/std/core/mem.c3
index f862debbb..1ddaf4b09 100644
--- a/lib/std/core/mem.c3
+++ b/lib/std/core/mem.c3
@@ -126,7 +126,7 @@ fn void free(void* ptr) @builtin
 /**
  * Run with a specific allocator inside of the macro body.
  **/
-macro void @with_allocator(Allocator* allocator; @body())
+macro void @scoped(Allocator* allocator; @body())
 {
 	Allocator* old_allocator = thread_allocator;
 	thread_allocator = allocator;
@@ -134,12 +134,52 @@ macro void @with_allocator(Allocator* allocator; @body())
 	@body();
 }
 
-fn void*! talloc(usize size)
+macro void @tscoped(;@body())
 {
-    return temp_allocator.alloc(size);
+	Allocator* old_allocator = thread_allocator;
+	TempAllocator* temp = temp_allocator();
+	usize mark = temp.mark()!!;
+	thread_allocator = temp;
+	defer temp.reset(mark);
+	defer thread_allocator = old_allocator;
+	@body();
+}
+
+fn void* talloc(usize size, usize alignment = 0)
+{
+    return temp_allocator().alloc(size, alignment)!!;
+}
+
+fn void* tcalloc(usize size, usize alignment = 0)
+{
+	return temp_allocator().calloc(size, alignment)!!;
+}
+
+fn void* trealloc(void* ptr, usize size, usize alignment = 0)
+{
+	return temp_allocator().realloc(ptr, size, alignment)!!;
+}
+
+macro void @pool(;@body) @builtin
+{
+	TempAllocator* temp = temp_allocator();
+	usize mark = temp.used;
+	defer temp.reset(mark);
+	@body();
 }
 
 private tlocal Allocator* thread_allocator = allocator::LIBC_ALLOCATOR;
+private tlocal TempAllocator* thread_temp_allocator = null;
+
+macro TempAllocator* temp_allocator()
+{
+	if (!thread_temp_allocator)
+	{
+		thread_temp_allocator = allocator::new_temp(env::TEMP_ALLOCATOR_SIZE, allocator::LIBC_ALLOCATOR)!!;
+	}
+	return thread_temp_allocator;
+}
+
 macro Allocator* current_allocator()
 {
 	return thread_allocator;
diff --git a/lib/std/core/mem_allocator.c3 b/lib/std/core/mem_allocator.c3
index 13e427101..021f207ab 100644
--- a/lib/std/core/mem_allocator.c3
+++ b/lib/std/core/mem_allocator.c3
@@ -22,12 +22,14 @@ enum AllocationKind
     REALLOC,
     FREE,
     RESET,
+    MARK,
 }
 
 fault AllocationFailure
 {
     OUT_OF_MEMORY,
     UNSUPPORTED_OPERATION,
+    CHUNK_TOO_LARGE,
 }
 
 
@@ -48,6 +50,11 @@ fn void*! Allocator.realloc(Allocator* allocator, void* old_pointer, usize size,
 	return allocator.function(allocator, size, alignment, old_pointer, REALLOC);
 }
 
+fn usize! Allocator.mark(Allocator* allocator) @inline
+{
+	return (usize)(uptr)allocator.function(allocator, 0, 0, null, MARK);
+}
+
 /**
  * @require !alignment || math::is_power_of_2(alignment)
  */
@@ -61,9 +68,9 @@ fn void! Allocator.free(Allocator* allocator, void* old_pointer) @inline
 	allocator.function(allocator, 0, 0, old_pointer, FREE)?;
 }
 
-fn void Allocator.reset(Allocator* allocator)
+fn void Allocator.reset(Allocator* allocator, usize mark = 0)
 {
-	allocator.function(allocator, 0, 0, null, RESET)!!;
+	allocator.function(allocator, mark, 0, null, RESET)!!;
 }
 
 private fn usize alignment_for_allocation(usize alignment) @inline
@@ -121,11 +128,10 @@ fn void DynamicArenaAllocator.destroy(DynamicArenaAllocator* this)
 }
 
 
-struct MemoryArena
+struct ArenaAllocator
 {
 	inline Allocator allocator;
-	void* memory;
-	usize total;
+	char[] data;
 	usize used;
 }
 
@@ -134,18 +140,17 @@ struct MemoryArena
  *
  * @require this != null
  **/
-fn void MemoryArena.init(MemoryArena* this, char[] data)
+fn void ArenaAllocator.init(ArenaAllocator* this, char[] data)
 {
 	this.function = &arena_allocator_function;
-	this.memory = data.ptr;
-	this.total = data.len;
+	this.data = data;
 	this.used = 0;
 }
 
 /**
  * @require this != null
  **/
-fn void MemoryArena.reset(MemoryArena* this)
+fn void ArenaAllocator.reset(ArenaAllocator* this)
 {
 	this.used = 0;
 }
\ No newline at end of file
diff --git a/lib/std/core/mem_array.c3 b/lib/std/core/mem_array.c3
index e87869bdd..a9e7bcabe 100644
--- a/lib/std/core/mem_array.c3
+++ b/lib/std/core/mem_array.c3
@@ -12,11 +12,29 @@ macro alloc($Type, usize elements)
     return ptr[:elements];
 }
 
+/**
+ * @require usize.max / elements > $Type.sizeof
+ **/
+macro talloc($Type, usize elements)
+{
+    $Type* ptr = mem::talloc($Type.sizeof * elements, $alignof($Type[1]));
+    return ptr[:elements];
+}
+
 /**
  * @require (usize.max / elements > $Type.sizeof)
  **/
 macro make($Type, usize elements)
 {
-    $Type* ptr = mem::calloc($sizeof($Type) * elements, $alignof($Type));
+    $Type* ptr = mem::calloc($sizeof($Type) * elements, $alignof($Type[1]));
+    return ptr[:elements];
+}
+
+/**
+ * @require (usize.max / elements > $Type.sizeof)
+ **/
+macro tmake($Type, usize elements)
+{
+    $Type* ptr = mem::tcalloc($sizeof($Type) * elements, $alignof($Type[1]));
     return ptr[:elements];
 }
diff --git a/lib/std/core/mem_temp_allocator.c3 b/lib/std/core/mem_temp_allocator.c3
deleted file mode 100644
index ca5eb3c79..000000000
--- a/lib/std/core/mem_temp_allocator.c3
+++ /dev/null
@@ -1,106 +0,0 @@
-module std::core::mem;
-
-const TEMP_BLOCK_SIZE = 1024;
-const TEMP_PAGES = 64;
-
-private char[TEMP_BLOCK_SIZE * TEMP_PAGES] allocator_static_storage;
-private void*[TEMP_PAGES] allocator_static_page_storage;
-
-SlotAllocator temp_allocator = {
-    .pages = &allocator_static_storage,
-    .page_size = TEMP_BLOCK_SIZE,
-    .page_count = TEMP_PAGES,
-    .bitmask = TEMP_PAGES - 1,
-    .current_page = 0,
-};
-
-struct SlotAllocator
-{
-    void* pages;
-    usize page_size;
-    usize page_count;
-    usize bitmask;
-    usize current_page;
-}
-
-fn void*! SlotAllocator.alloc(SlotAllocator *allocator, usize size)
-{
-    void* active_page = (char*)(allocator.pages) + allocator.current_page * allocator.page_size;
-    void** page_pointer = (void**)(active_page);
-    if (*page_pointer)
-    {
-        // TODO fix
-        thread_allocator.free(*page_pointer)?;
-        *page_pointer = null;
-    }
-    if (size > allocator.page_size - $sizeof(page_pointer))
-    {
-        void* mem = thread_allocator.alloc(size)?;
-        *page_pointer = mem;
-        allocator.current_page = (allocator.current_page + 1) & (allocator.bitmask);
-        return mem;
-    }
-    allocator.current_page = (allocator.current_page + 1) & (allocator.bitmask);
-    return &page_pointer[1];
-}
-
-
-struct RingAllocator
-{
-    char *data;
-    usize size;
-    usize offset;
-}
-
-
-fn void* RingAllocator.alloc(RingAllocator *allocator, usize size)
-{
-    if (size > allocator.size) return null;
-    // Wraparound? If so, start at the beginning.
-    if (allocator.offset + size > allocator.size)
-    {
-        allocator.offset = size;
-        return allocator.data;
-    }
-    void* data = allocator.offset + allocator.data;
-    allocator.offset = (allocator.offset + size) & allocator.size;
-    return data;
-}
-
-fn void* RingAllocator.realloc(RingAllocator *allocator, void* ptr, usize size)
-{
-    if (size > allocator.size) return null;
-    assert(allocator.data >= ptr && ptr < allocator.data + size, "Realloc on other allocator.");
-    // 1. The pointer is before the allocator
-    if (allocator.data + allocator.offset > ptr)
-    {
-        if (allocator.data + allocator.size < ptr + size)
-        {
-            // 1a. There is not enough space, we need to copy to the start.
-            usize pointer_offset = ptr - allocator.data;
-            usize copy_len = pointer_offset + size > allocator.offset ? allocator.offset - pointer_offset : size;
-            //memcpy(allocator.data, ptr, copy_len);
-            allocator.offset = size;
-            return allocator.data;
-        }
-        // 1b. There is enough space, so we just change the offset:
-        allocator.offset = ptr - allocator.data + size;
-        return ptr;
-    }
-    // 2. The pointer is after the allocator
-    // 2a. Is there sufficient space?
-    if (ptr + size <= allocator.data + allocator.size)
-    {
-        // Good, if so we simply change the offset and return the pointer.
-        allocator.offset = ptr - allocator.data + size;
-        return ptr;
-    }
-    // 2b. Not sufficient space, we copy to the beginning.
-    usize pointer_offset = ptr - allocator.data;
-    usize copy_len = allocator.size - (ptr - allocator.data);
-    if (copy_len > size) copy_len = size;
-    //memcpy(allocator.data, ptr, copy_len);
-    allocator.offset = size;
-    return allocator.data;
-}
-
diff --git a/lib/std/core/str.c3 b/lib/std/core/str.c3
index 02ba580e7..26c0e9c20 100644
--- a/lib/std/core/str.c3
+++ b/lib/std/core/str.c3
@@ -42,7 +42,7 @@ fn ZString copy_zstring(char[] s)
 fn ZString tcopy_zstring(char[] s)
 {
     usize len = s.len;
-    char* str = mem::talloc(len + 1)!!;
+    char* str = mem::talloc(len + 1);
     mem::copy(str, s.ptr, len);
     str[len] = 0;
     return (ZString)str;
@@ -129,7 +129,7 @@ fn char[] tcopy(char[] s)
 fn char[] tconcat(char[] s1, char[] s2)
 {
     usize full_len = s1.len + s2.len;
-    char* str = mem::talloc(full_len + 1)!!;
+    char* str = mem::talloc(full_len + 1);
     usize s1_len = s1.len;
     mem::copy(str, s1.ptr, s1_len);
     mem::copy(str + s1_len, s2.ptr, s2.len);
diff --git a/lib/std/io.c3 b/lib/std/io.c3
index e61af425c..eb19789e2 100644
--- a/lib/std/io.c3
+++ b/lib/std/io.c3
@@ -41,8 +41,8 @@ fn int println(char *message = "") @inline
 
 fn void! File.open(File* file, char[] filename, char[] mode)
 {
-    char* filename_copy = mem::talloc(filename.len + 1)!!;
-    char* mode_copy = mem::talloc(mode.len + 1)!!;
+    char* filename_copy = mem::talloc(filename.len + 1);
+    char* mode_copy = mem::talloc(mode.len + 1);
 
     mem::copy(filename_copy, (char*)(filename), filename.len);
     mem::copy(mode_copy, (char*)(mode), mode.len);
diff --git a/lib/std/io_printf.c3 b/lib/std/io_printf.c3
index dbc0a12b5..d03662632 100644
--- a/lib/std/io_printf.c3
+++ b/lib/std/io_printf.c3
@@ -674,7 +674,7 @@ private fn NtoaType int_from_variant(variant arg, bool *is_neg)
 
 	if (arg.type.kind == TypeKind.POINTER)
 	{
-		return (NtoaType)(uptr)(void*)arg.ptr;
+		return (NtoaType)(uptr)*(void**)arg.ptr;
 	}
 	switch (arg)
 	{
@@ -873,7 +873,6 @@ private fn usize! vsnprintf(OutputFn out, void* data, char[] format, variant[] v
 				out_str(&param, current)?;
 				continue;
 			case 'p':
-				param.width = (uint)(void*.sizeof * 2);
 				param.flags.zeropad = true;
 				param.flags.hash = true;
 				base = 16;
diff --git a/lib/std/libc.c3 b/lib/std/libc.c3
index ee314d55e..a20f03f96 100644
--- a/lib/std/libc.c3
+++ b/lib/std/libc.c3
@@ -87,6 +87,7 @@ extern fn usize strxfrm(char* dest, char* src, usize n);
 
 // malloc
 extern fn void* malloc(usize size);
+extern fn void* aligned_alloc(usize align, usize size);
 extern fn void* calloc(usize count, usize size);
 extern fn void* free(void*);
 extern fn void* realloc(void* ptr, usize size);
@@ -95,11 +96,14 @@ extern fn void* realloc(void* ptr, usize size);
 
 define Fpos = long;
 define CFile = void*;
+
 $switch (env::OS_TYPE):
 $case OsType.LINUX:
     extern CFile __stdin @extname("stdin");
     extern CFile __stdout @extname("stdout");
     extern CFile __stderr @extname("stderr");
+    extern fn usize malloc_usable_size(void* ptr);
+    macro usize malloc_size(void* ptr) { return malloc_usable_size(ptr); }
     macro CFile stdin() { return __stdin; }
     macro CFile stdout() { return __stdout; }
     macro CFile stderr() { return __stderr; }
@@ -107,11 +111,14 @@ $case OsType.MACOSX:
     extern CFile __stdinp;
     extern CFile __stdoutp;
     extern CFile __stderrp;
+    extern fn usize malloc_size(void* ptr);
     macro CFile stdin() { return __stdinp; }
     macro CFile stdout() { return __stdoutp; }
     macro CFile stderr() { return __stderrp; }
 $case OsType.WIN32:
     extern fn CFile __acrt_iob_func(CInt c);
+    extern fn usize _msize(void* ptr);
+    macro usize malloc_size(void* ptr) { return _msize(ptr); }
     macro CFile stdin() { return __acrt_iob_func(0); }
     macro CFile stdout() { return __acrt_iob_func(1); }
     macro CFile stderr() { return __acrt_iob_func(2); }
@@ -121,6 +128,11 @@ $default:
     macro CFile stderr() { return (CFile*)(uptr)2; }
 $endswitch;
 
+const HAS_MALLOC_SIZE =
+	env::OS_TYPE == OsType.LINUX
+	|| env::OS_TYPE == OsType.WIN32
+	|| env::OS_TYPE == OsType.MACOSX;
+
 // The following needs to be set per arch+os
 // For now I have simply pulled the defaults from MacOS
 const int SEEK_SET = 0;
diff --git a/resources/examples/contextfree/boolerr.c3 b/resources/examples/contextfree/boolerr.c3
index 7dbea9a47..7c8f3731f 100644
--- a/resources/examples/contextfree/boolerr.c3
+++ b/resources/examples/contextfree/boolerr.c3
@@ -121,7 +121,7 @@ fn void main()
 	dynamic_arena.init(1024);
     foreach (char[] url : URLS)
     {
-        mem::@with_allocator(&dynamic_arena)
+        mem::@scoped(&dynamic_arena)
         {
             io::printf(`Checking "https://%s/":` "\n", url);
             Summary summary = readAndBuildSummary(url);
diff --git a/src/version.h b/src/version.h
index c84e960e6..8279291c0 100644
--- a/src/version.h
+++ b/src/version.h
@@ -1 +1 @@
-#define COMPILER_VERSION "0.3.1"
\ No newline at end of file
+#define COMPILER_VERSION "0.3.2"
\ No newline at end of file