diff --git a/lib/std/collections/anylist.c3 b/lib/std/collections/anylist.c3
index ae263be0f..6c6254c76 100644
--- a/lib/std/collections/anylist.c3
+++ b/lib/std/collections/anylist.c3
@@ -44,7 +44,7 @@ fn AnyList* AnyList.init(&self, Allocator allocator, usz initial_capacity = 16)
 *>
 fn AnyList* AnyList.tinit(&self, usz initial_capacity = 16)
 {
-	return self.init(tmem(), initial_capacity) @inline;
+	return self.init(tmem, initial_capacity) @inline;
 }
 
 fn bool AnyList.is_initialized(&self) @inline => self.allocator != null;
@@ -74,7 +74,7 @@ fn usz? AnyList.to_format(&self, Formatter* formatter) @dynamic
 *>
 macro void AnyList.push(&self, element)
 {
-	if (!self.allocator) self.allocator = tmem();
+	if (!self.allocator) self.allocator = tmem;
 	self.append_internal(allocator::clone(self.allocator, element));
 }
 
@@ -121,7 +121,7 @@ fn any? AnyList.copy_pop(&self, Allocator allocator)
  Pop the last value and allocate the copy using the temp allocator
  @return? NO_MORE_ELEMENT
 *>
-fn any? AnyList.tcopy_pop(&self) => self.copy_pop(tmem());
+fn any? AnyList.tcopy_pop(&self) => self.copy_pop(tmem);
 
 <*
  Pop the last value. It must later be released using list.free_element()
@@ -177,7 +177,7 @@ fn any? AnyList.copy_pop_first(&self, Allocator allocator)
 <*
  Same as temp_pop() but pops the first value instead.
 *>
-fn any? AnyList.tcopy_pop_first(&self) => self.copy_pop_first(tmem());
+fn any? AnyList.tcopy_pop_first(&self) => self.copy_pop_first(tmem);
 
 <*
  @require index < self.size
@@ -415,7 +415,7 @@ fn void AnyList.reserve(&self, usz min_capacity)
 {
 	if (!min_capacity) return;
 	if (self.capacity >= min_capacity) return;
-	if (!self.allocator) self.allocator = tmem();
+	if (!self.allocator) self.allocator = tmem;
 	min_capacity = math::next_power_of_2(min_capacity);
 	self.entries = allocator::realloc(self.allocator, self.entries, any.sizeof * min_capacity);
 	self.capacity = min_capacity;
diff --git a/lib/std/collections/bitset.c3 b/lib/std/collections/bitset.c3
index 3681efed4..0ef405010 100644
--- a/lib/std/collections/bitset.c3
+++ b/lib/std/collections/bitset.c3
@@ -94,7 +94,7 @@ fn GrowableBitSet* GrowableBitSet.init(&self, Allocator allocator, usz initial_c
 
 fn GrowableBitSet* GrowableBitSet.tinit(&self, usz initial_capacity = 1)
 {
-	return self.init(tmem(), initial_capacity) @inline;
+	return self.init(tmem, initial_capacity) @inline;
 }
 
 fn void GrowableBitSet.free(&self)
diff --git a/lib/std/collections/elastic_array.c3 b/lib/std/collections/elastic_array.c3
index cd8f36eb4..297dd049a 100644
--- a/lib/std/collections/elastic_array.c3
+++ b/lib/std/collections/elastic_array.c3
@@ -169,9 +169,9 @@ macro Type[] ElasticArray.to_array(&self, Allocator allocator)
 fn Type[] ElasticArray.to_tarray(&self)
 {
 	$if type_is_overaligned():
-	return self.to_aligned_array(tmem());
+	return self.to_aligned_array(tmem);
 	$else
-	return self.to_array(tmem());
+	return self.to_array(tmem);
 	$endif;
 }
 
diff --git a/lib/std/collections/hashmap.c3 b/lib/std/collections/hashmap.c3
index 94943c02c..4809e1175 100644
--- a/lib/std/collections/hashmap.c3
+++ b/lib/std/collections/hashmap.c3
@@ -61,7 +61,7 @@ fn HashMap* HashMap.init(&self, Allocator allocator, uint capacity = DEFAULT_INI
 *>
 fn HashMap* HashMap.tinit(&self, uint capacity = DEFAULT_INITIAL_CAPACITY, float load_factor = DEFAULT_LOAD_FACTOR)
 {
-	return self.init(tmem(), capacity, load_factor) @inline;
+	return self.init(tmem, capacity, load_factor) @inline;
 }
 
 <*
@@ -90,7 +90,7 @@ macro HashMap* HashMap.init_with_key_values(&self, Allocator allocator, ..., uin
 *>
 macro HashMap* HashMap.tinit_with_key_values(&self, ..., uint capacity = DEFAULT_INITIAL_CAPACITY, float load_factor = DEFAULT_LOAD_FACTOR)
 {
-	return self.tinit_with_key_values(tmem(), capacity, load_factor);
+	return self.tinit_with_key_values(tmem, capacity, load_factor);
 }
 
 <*
@@ -126,7 +126,7 @@ fn HashMap* HashMap.init_from_keys_and_values(&self, Allocator allocator, Key[]
 *>
 fn HashMap* HashMap.tinit_from_keys_and_values(&self, Key[] keys, Value[] values, uint capacity = DEFAULT_INITIAL_CAPACITY, float load_factor = DEFAULT_LOAD_FACTOR)
 {
-	return self.init_from_keys_and_values(tmem(), keys, values, capacity, load_factor);
+	return self.init_from_keys_and_values(tmem, keys, values, capacity, load_factor);
 }
 
 <*
@@ -158,7 +158,7 @@ fn HashMap* HashMap.init_from_map(&self, Allocator allocator, HashMap* other_map
 *>
 fn HashMap* HashMap.tinit_from_map(&map, HashMap* other_map)
 {
-	return map.init_from_map(tmem(), other_map) @inline;
+	return map.init_from_map(tmem, other_map) @inline;
 }
 
 fn bool HashMap.is_empty(&map) @inline
@@ -287,7 +287,7 @@ fn void HashMap.free(&map)
 
 fn Key[] HashMap.tkeys(&self)
 {
-	return self.keys(tmem()) @inline;
+	return self.keys(tmem) @inline;
 }
 
 fn Key[] HashMap.keys(&self, Allocator allocator)
@@ -334,7 +334,7 @@ macro HashMap.@each_entry(map; @body(entry))
 
 fn Value[] HashMap.tvalues(&map)
 {
-	return map.values(tmem()) @inline;
+	return map.values(tmem) @inline;
 }
 
 fn Value[] HashMap.values(&self, Allocator allocator)
diff --git a/lib/std/collections/linkedlist.c3 b/lib/std/collections/linkedlist.c3
index 9d5fce0f0..b27c45cbc 100644
--- a/lib/std/collections/linkedlist.c3
+++ b/lib/std/collections/linkedlist.c3
@@ -32,7 +32,7 @@ fn LinkedList* LinkedList.init(&self, Allocator allocator)
 
 fn LinkedList* LinkedList.tinit(&self)
 {
-	return self.init(tmem()) @inline;
+	return self.init(tmem) @inline;
 }
 
 fn bool LinkedList.is_initialized(&self) @inline => self.allocator != null;
@@ -47,7 +47,7 @@ macro void LinkedList.free_node(&self, Node* node) @private
 
 macro Node* LinkedList.alloc_node(&self) @private
 {
-	if (!self.allocator) self.allocator = tmem();
+	if (!self.allocator) self.allocator = tmem;
 	return allocator::alloc(self.allocator, Node);
 }
 
diff --git a/lib/std/collections/list.c3 b/lib/std/collections/list.c3
index 585435288..65369642b 100644
--- a/lib/std/collections/list.c3
+++ b/lib/std/collections/list.c3
@@ -45,7 +45,7 @@ fn List* List.init(&self, Allocator allocator, usz initial_capacity = 16)
 *>
 fn List* List.tinit(&self, usz initial_capacity = 16)
 {
-	return self.init(tmem(), initial_capacity) @inline;
+	return self.init(tmem, initial_capacity) @inline;
 }
 
 <*
@@ -173,9 +173,9 @@ macro Type[] List.to_array(&self, Allocator allocator)
 fn Type[] List.to_tarray(&self)
 {
 	$if type_is_overaligned():
-	return self.to_aligned_array(tmem());
+	return self.to_aligned_array(tmem);
 	$else
-	return self.to_array(tmem());
+	return self.to_array(tmem);
 	$endif;
 }
 
@@ -354,7 +354,7 @@ fn void List.ensure_capacity(&self, usz min_capacity) @local
 		case &dummy:
 			self.allocator = mem;
 		case null:
-			self.allocator = tmem();
+			self.allocator = tmem;
 		default:
 			break;
 	}
diff --git a/lib/std/collections/priorityqueue.c3 b/lib/std/collections/priorityqueue.c3
index 64d9a595d..253a050cc 100644
--- a/lib/std/collections/priorityqueue.c3
+++ b/lib/std/collections/priorityqueue.c3
@@ -42,7 +42,7 @@ fn PrivatePriorityQueue* PrivatePriorityQueue.init(&self, Allocator allocator, u
 
 fn PrivatePriorityQueue* PrivatePriorityQueue.tinit(&self, usz initial_capacity = 16) @inline
 {
-	self.init(tmem(), initial_capacity);
+	self.init(tmem, initial_capacity);
 	return self;
 }
 
diff --git a/lib/std/compression/qoi.c3 b/lib/std/compression/qoi.c3
index eecfa4dd9..cf95907bb 100644
--- a/lib/std/compression/qoi.c3
+++ b/lib/std/compression/qoi.c3
@@ -66,7 +66,7 @@ import std::io;
 fn usz? write(String filename, char[] input, QOIDesc* desc) => @pool()
 {
 	// encode data
-	char[] output = encode(tmem(), input, desc)!;
+	char[] output = encode(tmem, input, desc)!;
 
 	file::save(filename, output)!;
 	return output.len;
diff --git a/lib/std/core/allocators/tracking_allocator.c3 b/lib/std/core/allocators/tracking_allocator.c3
index 2591ec02a..b026df40f 100644
--- a/lib/std/core/allocators/tracking_allocator.c3
+++ b/lib/std/core/allocators/tracking_allocator.c3
@@ -155,7 +155,7 @@ fn void? TrackingAllocator.fprint_report(&self, OutStream out) => @pool()
 				Backtrace trace = backtrace::BACKTRACE_UNKNOWN;
 				if (allocation.backtrace[3])
 				{
-					trace = backtrace::symbolize_backtrace(tmem(), allocation.backtrace[3:1]).get(0) ?? backtrace::BACKTRACE_UNKNOWN;
+					trace = backtrace::symbolize_backtrace(tmem, allocation.backtrace[3:1]).get(0) ?? backtrace::BACKTRACE_UNKNOWN;
 				}
 				if (trace.function.len)	leaks = true;
 				io::fprintfn(out, "%13s   %p   %s:%d", allocation.size,
@@ -194,7 +194,7 @@ fn void? TrackingAllocator.fprint_report(&self, OutStream out) => @pool()
 					break;
 				}
 			}
-			BacktraceList list = backtrace::symbolize_backtrace(tmem(), allocation.backtrace[3..(end - 1)])!;
+			BacktraceList list = backtrace::symbolize_backtrace(tmem, allocation.backtrace[3..(end - 1)])!;
 			io::fprintfn(out, "Allocation %d (%d bytes): ", i + 1, allocation.size)!;
 			foreach (trace : list)
 			{
diff --git a/lib/std/core/array.c3 b/lib/std/core/array.c3
index f22c957c6..dca56a592 100644
--- a/lib/std/core/array.c3
+++ b/lib/std/core/array.c3
@@ -81,7 +81,7 @@ macro concat(Allocator allocator, arr1, arr2) @nodiscard
  @require @typeis(arr1[0], $typeof(arr2[0])) : "Arrays must have the same type"
  @ensure return.len == arr1.len + arr2.len
 *>
-macro tconcat(arr1, arr2) @nodiscard => concat(tmem(), arr1, arr2);
+macro tconcat(arr1, arr2) @nodiscard => concat(tmem, arr1, arr2);
 
 module std::core::array::slice{Type};
 
diff --git a/lib/std/core/builtin.c3 b/lib/std/core/builtin.c3
index dd19c7698..c2267dad3 100644
--- a/lib/std/core/builtin.c3
+++ b/lib/std/core/builtin.c3
@@ -90,7 +90,7 @@ macro anycast(any v, $Type) @builtin
 
 fn bool print_backtrace(String message, int backtraces_to_ignore) @if(env::NATIVE_STACKTRACE) => @stack_mem(0x1100; Allocator smem)
 {
-	TempAllocator* t = allocator::current_temp;
+	Allocator t = allocator::current_temp;
 	TempAllocator* new_t = allocator::new_temp_allocator(smem, 0x1000)!!;
 	allocator::current_temp = new_t;
 	defer
@@ -101,7 +101,7 @@ fn bool print_backtrace(String message, int backtraces_to_ignore) @if(env::NATIV
 	void*[256] buffer;
 	void*[] backtraces = backtrace::capture_current(&buffer);
 	backtraces_to_ignore++;
-	BacktraceList? backtrace = backtrace::symbolize_backtrace(tmem(), backtraces);
+	BacktraceList? backtrace = backtrace::symbolize_backtrace(tmem, backtraces);
 	if (catch backtrace) return false;
 	if (backtrace.len() <= backtraces_to_ignore) return false;
 	io::eprint("\nERROR: '");
diff --git a/lib/std/core/dstring.c3 b/lib/std/core/dstring.c3
index 712b051fd..cedb31e1c 100644
--- a/lib/std/core/dstring.c3
+++ b/lib/std/core/dstring.c3
@@ -24,7 +24,7 @@ fn DString DString.init(&self, Allocator allocator, usz capacity = MIN_CAPACITY)
 *>
 fn DString DString.tinit(&self, usz capacity = MIN_CAPACITY)
 {
-	return self.init(tmem(), capacity) @inline;
+	return self.init(tmem, capacity) @inline;
 }
 
 fn DString new_with_capacity(Allocator allocator, usz capacity)
@@ -32,7 +32,7 @@ fn DString new_with_capacity(Allocator allocator, usz capacity)
 	return (DString){}.init(allocator, capacity);
 }
 
-fn DString temp_with_capacity(usz capacity) => new_with_capacity(tmem(), capacity) @inline;
+fn DString temp_with_capacity(usz capacity) => new_with_capacity(tmem, capacity) @inline;
 
 fn DString new(Allocator allocator, String c = "")
 {
@@ -46,7 +46,7 @@ fn DString new(Allocator allocator, String c = "")
 	return (DString)data;
 }
 
-fn DString temp(String s = "") => new(tmem(), s) @inline;
+fn DString temp(String s = "") => new(tmem, s) @inline;
 
 
 fn void DString.replace_char(self, char ch, char replacement)
@@ -108,7 +108,7 @@ fn DString DString.concat(self, Allocator allocator, DString b)
 	return string;
 }
 
-fn DString DString.tconcat(self, DString b) => self.concat(tmem(), b);
+fn DString DString.tconcat(self, DString b) => self.concat(tmem, b);
 
 fn ZString DString.zstr_view(&self)
 {
@@ -218,7 +218,7 @@ fn usz DString.append_char32(&self, Char32 c)
 	return n;
 }
 
-fn DString DString.tcopy(&self) => self.copy(tmem());
+fn DString DString.tcopy(&self) => self.copy(tmem);
 
 fn DString DString.copy(self, Allocator allocator)
 {
@@ -248,7 +248,7 @@ fn String DString.copy_str(self, Allocator allocator)
 	return (String)self.copy_zstr(allocator)[:self.len()];
 }
 
-fn String DString.tcopy_str(self) => self.copy_str(tmem()) @inline;
+fn String DString.tcopy_str(self) => self.copy_str(tmem) @inline;
 
 fn bool DString.equals(self, DString other_string)
 {
@@ -536,15 +536,13 @@ macro void DString.insert_at(&self, usz index, value)
 	$endswitch
 }
 
+import libc;
 fn usz? DString.appendf(&self, String format, args...) @maydiscard
 {
 	if (!self.data()) self.tinit(format.len + 20);
-	@pool()
-	{
-		Formatter formatter;
-		formatter.init(&out_string_append_fn, self);
-		return formatter.vprintf(format, args);
-	};
+	Formatter formatter;
+	formatter.init(&out_string_append_fn, self);
+	return formatter.vprintf(format, args);
 }
 
 fn usz? DString.appendfn(&self, String format, args...) @maydiscard
diff --git a/lib/std/core/mem.c3 b/lib/std/core/mem.c3
index 94b84fd1f..e4eccd22b 100644
--- a/lib/std/core/mem.c3
+++ b/lib/std/core/mem.c3
@@ -571,6 +571,19 @@ fn void temp_pop(PoolState old_state)
 	allocator::pop_pool(old_state) @inline;
 }
 
+macro void @pool_init(Allocator allocator, usz pool_size, usz buffer_size; @body) @builtin
+{
+	Allocator current = allocator::current_temp;
+	TempAllocator* top = allocator::top_temp;
+	allocator::create_temp_allocator(allocator, pool_size, buffer_size);
+	defer
+	{
+		allocator::destroy_temp_allocators();
+		allocator::top_temp = top;
+		allocator::current_temp = current;
+	}
+	@body();
+}
 macro void @pool(;@body) @builtin
 {
 	PoolState state = allocator::push_pool() @inline;
@@ -636,7 +649,7 @@ fn void* malloc_aligned(usz size, usz alignment) @builtin @inline @nodiscard
 fn void* tmalloc(usz size, usz alignment = 0) @builtin @inline @nodiscard
 {
 	if (!size) return null;
-	return tmem().acquire(size, NO_ZERO, alignment)!!;
+	return tmem.acquire(size, NO_ZERO, alignment)!!;
 }
 
 <*
@@ -814,7 +827,7 @@ fn void* calloc_aligned(usz size, usz alignment) @builtin @inline @nodiscard
 fn void* tcalloc(usz size, usz alignment = 0) @builtin @inline @nodiscard
 {
 	if (!size) return null;
-	return tmem().acquire(size, ZERO, alignment)!!;
+	return tmem.acquire(size, ZERO, alignment)!!;
 }
 
 fn void* realloc(void *ptr, usz new_size) @builtin @inline @nodiscard
@@ -841,7 +854,7 @@ fn void* trealloc(void* ptr, usz size, usz alignment = mem::DEFAULT_MEM_ALIGNMEN
 {
 	if (!size) return null;
 	if (!ptr) return tmalloc(size, alignment);
-	return tmem().resize(ptr, size, alignment)!!;
+	return tmem.resize(ptr, size, alignment)!!;
 }
 
 module std::core::mem @if(env::NO_LIBC);
diff --git a/lib/std/core/mem_allocator.c3 b/lib/std/core/mem_allocator.c3
index 93fee8087..72ab37e26 100644
--- a/lib/std/core/mem_allocator.c3
+++ b/lib/std/core/mem_allocator.c3
@@ -359,10 +359,12 @@ alias mem @builtin = thread_allocator ;
 tlocal Allocator thread_allocator @private = base_allocator();
 Allocator temp_base_allocator @private = base_allocator();
 
-typedef PoolState = void*;
+typedef PoolState = TempAllocator*;
 
-tlocal TempAllocator* current_temp;
+const LazyTempAllocator LAZY_TEMP @private = {};
+tlocal Allocator current_temp = &LAZY_TEMP;
 tlocal TempAllocator* top_temp;
+tlocal bool auto_create_temp = false;
 
 usz temp_allocator_min_size = temp_allocator_default_min_size();
 usz temp_allocator_buffer_size = temp_allocator_default_buffer_size();
@@ -370,16 +372,16 @@ usz temp_allocator_new_mult = 4;
 
 fn PoolState push_pool()
 {
-	TempAllocator* old = current_temp ?: create_temp_allocator();
-	current_temp = current_temp.derive_allocator(temp_allocator_min_size, temp_allocator_buffer_size, temp_allocator_new_mult)!!;
-	return (PoolState)old;
+	Allocator old = top_temp ? current_temp : create_temp_allocator_on_demand();
+	current_temp = ((TempAllocator*)old).derive_allocator(temp_allocator_min_size, temp_allocator_buffer_size, temp_allocator_new_mult)!!;
+	return (PoolState)old.ptr;
 }
 
 fn void pop_pool(PoolState old)
 {
-	current_temp = (TempAllocator*)old;
-	current_temp.reset();
-
+	TempAllocator* temp = (TempAllocator*)old;
+	current_temp = temp;
+	temp.reset();
 }
 
 macro Allocator base_allocator() @private
@@ -424,18 +426,36 @@ macro usz temp_allocator_default_buffer_size() @local
 macro Allocator heap() => thread_allocator;
 
 <*
- @require !current_temp : "This should never be called when temp already exists"
+ @require !top_temp : "This should never be called when temp already exists"
 *>
-fn TempAllocator* create_temp_allocator() @private
+fn Allocator create_temp_allocator_on_demand() @private
 {
-	return top_temp = current_temp = allocator::new_temp_allocator(base_allocator(), temp_allocator_size())!!;
+	if (!auto_create_temp)
+	{
+	    auto_create_temp = true;
+	    abort("Only the main thread pool is implicitly created. Use '@pool_init()' to enable the temp allocator on other threads.");
+	}
+	return create_temp_allocator(base_allocator(), temp_allocator_size());
 }
-macro Allocator temp()
+<*
+ @require !top_temp : "This should never be called when temp already exists"
+*>
+fn Allocator create_temp_allocator(Allocator allocator, usz size, usz buffer = temp_allocator_default_buffer_size()) @private
 {
-	return current_temp ?: create_temp_allocator();
+	return current_temp = top_temp = allocator::new_temp_allocator(allocator, size)!!;
 }
 
-alias tmem @builtin = temp;
+macro Allocator temp()
+{
+	return current_temp;
+}
+
+alias tmem @builtin = current_temp;
+
+fn void allow_implicit_temp_allocator_on_load_thread() @init(1) @local @if(env::LIBC)
+{
+	auto_create_temp = true;
+}
 
 fn void destroy_temp_allocators_after_exit() @finalizer(65535) @local @if(env::LIBC)
 {
@@ -449,6 +469,27 @@ fn void destroy_temp_allocators()
 {
 	if (!top_temp) return;
 	top_temp.free();
+	top_temp = null;
+	current_temp = &LAZY_TEMP;
+}
+
+import libc;
+typedef LazyTempAllocator (Allocator) @private = uptr;
+
+fn void*? LazyTempAllocator.acquire(&self, usz bytes, AllocInitType init_type, usz alignment) @dynamic
+{
+	if (!top_temp) create_temp_allocator_on_demand();
+	return top_temp.acquire(bytes, init_type, alignment);
+}
+
+fn void*? LazyTempAllocator.resize(&self, void* old_ptr, usz new_bytes, usz alignment) @dynamic
+{
+	if (!top_temp) create_temp_allocator_on_demand();
+	return top_temp.resize(old_ptr, new_bytes, alignment);
+}
+
+fn void LazyTempAllocator.release(&self, void* old_ptr, bool aligned) @dynamic
+{
 }
 
 const NullAllocator NULL_ALLOCATOR = {};
diff --git a/lib/std/core/runtime_benchmark.c3 b/lib/std/core/runtime_benchmark.c3
index c0f4e582a..0cb98d1f8 100644
--- a/lib/std/core/runtime_benchmark.c3
+++ b/lib/std/core/runtime_benchmark.c3
@@ -96,5 +96,5 @@ fn bool run_benchmarks(BenchmarkUnit[] benchmarks)
 
 fn bool default_benchmark_runner(String[] args) => @pool()
 {
-	return run_benchmarks(benchmark_collection_create(tmem()));
+	return run_benchmarks(benchmark_collection_create(tmem));
 }
diff --git a/lib/std/core/runtime_test.c3 b/lib/std/core/runtime_test.c3
index 6c41e1ec4..a0adce33e 100644
--- a/lib/std/core/runtime_test.c3
+++ b/lib/std/core/runtime_test.c3
@@ -329,6 +329,6 @@ fn bool run_tests(String[] args, TestUnit[] tests) @private
 fn bool default_test_runner(String[] args) => @pool()
 {
 	assert(test_context == null, "test suite is already running");
-	return run_tests(args, test_collection_create(tmem()));
+	return run_tests(args, test_collection_create(tmem));
 }
 
diff --git a/lib/std/core/string.c3 b/lib/std/core/string.c3
index 938cb284e..bec71f2f0 100644
--- a/lib/std/core/string.c3
+++ b/lib/std/core/string.c3
@@ -278,7 +278,7 @@ fn String[] String.split(s, Allocator allocator, String needle, usz max = 0, boo
  @param max : "Max number of elements, 0 means no limit, defaults to 0"
  @param skip_empty : "True to skip empty elements"
 *>
-fn String[] String.tsplit(s, String needle, usz max = 0, bool skip_empty = false) => s.split(tmem(), needle, max, skip_empty) @inline;
+fn String[] String.tsplit(s, String needle, usz max = 0, bool skip_empty = false) => s.split(tmem, needle, max, skip_empty) @inline;
 
 faultdef BUFFER_EXCEEDED;
 
@@ -516,10 +516,10 @@ fn String String.concat(s1, Allocator allocator, String s2)
 	return (String)str[:full_len];
 }
 
-fn String String.tconcat(s1, String s2) => s1.concat(tmem(), s2);
+fn String String.tconcat(s1, String s2) => s1.concat(tmem, s2);
 
 
-fn ZString String.zstr_tcopy(s) => s.zstr_copy(tmem()) @inline;
+fn ZString String.zstr_tcopy(s) => s.zstr_copy(tmem) @inline;
 
 <*
  Copy this string, by duplicating the string, always adding a zero byte
@@ -542,7 +542,7 @@ fn void String.free(&s, Allocator allocator)
 	*s = "";
 }
 
-fn String String.tcopy(s) => s.copy(tmem()) @inline;
+fn String String.tcopy(s) => s.copy(tmem) @inline;
 
 fn String ZString.copy(z, Allocator allocator)
 {
@@ -551,7 +551,7 @@ fn String ZString.copy(z, Allocator allocator)
 
 fn String ZString.tcopy(z)
 {
-	return z.str_view().copy(tmem()) @inline;
+	return z.str_view().copy(tmem) @inline;
 }
 
 <*
@@ -568,14 +568,14 @@ fn Char16[]? String.to_utf16(s, Allocator allocator)
 	return data[:len16];
 }
 
-fn Char16[]? String.to_temp_utf16(s) => s.to_utf16(tmem());
+fn Char16[]? String.to_temp_utf16(s) => s.to_utf16(tmem);
 
 fn WString? String.to_wstring(s, Allocator allocator)
 {
 	return (WString)s.to_utf16(allocator).ptr;
 }
 
-fn WString? String.to_temp_wstring(s) => s.to_wstring(tmem());
+fn WString? String.to_temp_wstring(s) => s.to_wstring(tmem);
 
 fn Char32[]? String.to_utf32(s, Allocator allocator)
 {
@@ -586,7 +586,7 @@ fn Char32[]? String.to_utf32(s, Allocator allocator)
 	return data[:codepoints];
 }
 
-fn Char32[]? String.to_temp_utf32(s) => s.to_utf32(tmem());
+fn Char32[]? String.to_temp_utf32(s) => s.to_utf32(tmem);
 
 <*
  Convert a string to ASCII lower case in place.
@@ -608,7 +608,7 @@ fn String String.to_lower_copy(s, Allocator allocator)
 
 fn String String.to_lower_tcopy(s)
 {
-	return s.to_lower_copy(tmem());
+	return s.to_lower_copy(tmem);
 }
 
 <*
@@ -648,7 +648,7 @@ fn StringIterator String.iterator(s)
 *>
 fn String String.to_upper_tcopy(s)
 {
-	return s.to_upper_copy(tmem());
+	return s.to_upper_copy(tmem);
 }
 
 fn String? from_utf32(Allocator allocator, Char32[] utf32)
@@ -679,8 +679,8 @@ fn String? from_wstring(Allocator allocator, WString wstring)
 	return from_utf16(allocator, utf16);
 }
 
-fn String? tfrom_wstring(WString wstring) => from_wstring(tmem(), wstring) @inline;
-fn String? tfrom_utf16(Char16[] utf16) => from_utf16(tmem(), utf16) @inline;
+fn String? tfrom_wstring(WString wstring) => from_wstring(tmem, wstring) @inline;
+fn String? tfrom_utf16(Char16[] utf16) => from_utf16(tmem, utf16) @inline;
 
 fn usz String.utf8_codepoints(s)
 {
@@ -839,4 +839,4 @@ macro String from_struct(Allocator allocator, x)
 	};
 }
 
-macro String tfrom_struct(x) => from_struct(tmem(), x);
+macro String tfrom_struct(x) => from_struct(tmem, x);
diff --git a/lib/std/encoding/base32.c3 b/lib/std/encoding/base32.c3
index 1fb5a6d5a..efc346d83 100644
--- a/lib/std/encoding/base32.c3
+++ b/lib/std/encoding/base32.c3
@@ -40,8 +40,8 @@ fn char[]? decode(Allocator allocator, char[] src, char padding = DEFAULT_PAD, B
 	return decode_buffer(src, dst, padding, alphabet);
 }
 
-fn String? tencode(char[] code, char padding = DEFAULT_PAD, Base32Alphabet* alphabet = &STANDARD) @inline => encode(tmem(), code, padding, alphabet);
-fn char[]? tdecode(char[] code, char padding = DEFAULT_PAD, Base32Alphabet* alphabet = &STANDARD) @inline => decode(tmem(), code, padding, alphabet);
+fn String? tencode(char[] code, char padding = DEFAULT_PAD, Base32Alphabet* alphabet = &STANDARD) @inline => encode(tmem, code, padding, alphabet);
+fn char[]? tdecode(char[] code, char padding = DEFAULT_PAD, Base32Alphabet* alphabet = &STANDARD) @inline => decode(tmem, code, padding, alphabet);
 
 <*
  Calculate the length in bytes of the decoded data.
diff --git a/lib/std/encoding/base64.c3 b/lib/std/encoding/base64.c3
index 4bb6ef92a..d01574415 100644
--- a/lib/std/encoding/base64.c3
+++ b/lib/std/encoding/base64.c3
@@ -55,8 +55,8 @@ fn char[]? decode(Allocator allocator, char[] src, char padding = DEFAULT_PAD, B
 	return decode_buffer(src, dst, padding, alphabet);
 }
 
-fn String tencode(char[] code, char padding = DEFAULT_PAD, Base64Alphabet* alphabet = &STANDARD) @inline => encode(tmem(), code, padding, alphabet);
-fn char[]? tdecode(char[] code, char padding = DEFAULT_PAD, Base64Alphabet* alphabet = &STANDARD) @inline => decode(tmem(), code, padding, alphabet);
+fn String tencode(char[] code, char padding = DEFAULT_PAD, Base64Alphabet* alphabet = &STANDARD) @inline => encode(tmem, code, padding, alphabet);
+fn char[]? tdecode(char[] code, char padding = DEFAULT_PAD, Base64Alphabet* alphabet = &STANDARD) @inline => decode(tmem, code, padding, alphabet);
 
 
 <*
diff --git a/lib/std/encoding/csv.c3 b/lib/std/encoding/csv.c3
index c60ef8179..7a7273968 100644
--- a/lib/std/encoding/csv.c3
+++ b/lib/std/encoding/csv.c3
@@ -51,7 +51,7 @@ fn CsvRow? CsvReader.read_row(self, Allocator allocator)
 
 fn CsvRow? CsvReader.tread_row(self)
 {
-	return self.read_row(tmem()) @inline;
+	return self.read_row(tmem) @inline;
 }
 
 <*
diff --git a/lib/std/encoding/hex.c3 b/lib/std/encoding/hex.c3
index 6e528ed3e..c2f28ad5d 100644
--- a/lib/std/encoding/hex.c3
+++ b/lib/std/encoding/hex.c3
@@ -25,8 +25,8 @@ fn char[]? decode(Allocator allocator, char[] code)
 	return data[:decode_bytes(code, data)!];
 }
 
-fn String tencode(char[] code) @inline => encode(tmem(), code);
-fn char[]? tdecode(char[] code) @inline => decode(tmem(), code);
+fn String tencode(char[] code) @inline => encode(tmem, code);
+fn char[]? tdecode(char[] code) @inline => decode(tmem, code);
 
 
 <*
diff --git a/lib/std/encoding/json.c3 b/lib/std/encoding/json.c3
index 65f9676db..461f12929 100644
--- a/lib/std/encoding/json.c3
+++ b/lib/std/encoding/json.c3
@@ -15,7 +15,7 @@ fn Object*? parse_string(Allocator allocator, String s)
 
 fn Object*? tparse_string(String s)
 {
-	return parse(tmem(), (ByteReader){}.init(s));
+	return parse(tmem, (ByteReader){}.init(s));
 }
 
 fn Object*? parse(Allocator allocator, InStream s)
@@ -32,7 +32,7 @@ fn Object*? parse(Allocator allocator, InStream s)
 
 fn Object*? tparse(InStream s)
 {
-	return parse(tmem(), s);
+	return parse(tmem, s);
 }
 
 // -- Implementation follows --
diff --git a/lib/std/io/file.c3 b/lib/std/io/file.c3
index 52b75b645..f06336a8b 100644
--- a/lib/std/io/file.c3
+++ b/lib/std/io/file.c3
@@ -201,7 +201,7 @@ fn char[]? load(Allocator allocator, String filename)
 
 fn char[]? load_path(Allocator allocator, Path path) => load(allocator, path.str_view());
 
-fn char[]? load_temp(String filename) => load(tmem(), filename);
+fn char[]? load_temp(String filename) => load(tmem, filename);
 
 fn char[]? load_path_temp(Path path) => load_temp(path.str_view());
 
diff --git a/lib/std/io/io.c3 b/lib/std/io/io.c3
index 9f24434f5..8bfe75985 100644
--- a/lib/std/io/io.c3
+++ b/lib/std/io/io.c3
@@ -98,7 +98,7 @@ macro String? readline(Allocator allocator, stream = io::stdin())
 *>
 macro String? treadline(stream = io::stdin())
 {
-	return readline(tmem(), stream) @inline;
+	return readline(tmem, stream) @inline;
 }
 
 <*
diff --git a/lib/std/io/path.c3 b/lib/std/io/path.c3
index 09ca26ea2..d98854c55 100644
--- a/lib/std/io/path.c3
+++ b/lib/std/io/path.c3
@@ -30,7 +30,7 @@ fn Path? cwd(Allocator allocator)
 {
 	@pool()
 	{
-		return new(allocator, os::getcwd(tmem()));
+		return new(allocator, os::getcwd(tmem));
 	};
 }
 
@@ -38,7 +38,7 @@ fn bool is_dir(Path path) => os::native_is_dir(path.str_view());
 fn bool is_file(Path path) => os::native_is_file(path.str_view());
 fn usz? file_size(Path path) => os::native_file_size(path.str_view());
 fn bool exists(Path path) => os::native_file_or_dir_exists(path.str_view());
-fn Path? tcwd() => cwd(tmem()) @inline;
+fn Path? tcwd() => cwd(tmem) @inline;
 
 <*
  @require @is_pathlike(path) : "Expected a Path or String to chdir"
@@ -150,7 +150,7 @@ fn Path? new(Allocator allocator, String path, PathEnv path_env = DEFAULT_ENV)
 *>
 fn Path? temp(String path, PathEnv path_env = DEFAULT_ENV)
 {
-	return new(tmem(), path, path_env);
+	return new(tmem, path, path_env);
 }
 
 fn Path? from_win32_wstring(Allocator allocator, WString path) => @pool()
@@ -193,7 +193,7 @@ fn Path? Path.append(self, Allocator allocator, String filename)
 	};
 }
 
-fn Path? Path.tappend(self, String filename) => self.append(tmem(), filename);
+fn Path? Path.tappend(self, String filename) => self.append(tmem, filename);
 
 fn usz? start_of_base_name(String str, PathEnv path_env) @local
 {
@@ -249,7 +249,7 @@ fn Path? Path.absolute(self, Allocator allocator)
 	{
 		@pool()
 		{
-			String cwd = os::getcwd(tmem())!;
+			String cwd = os::getcwd(tmem)!;
 			return new(allocator, cwd, self.env);
 		};
 	}
@@ -263,8 +263,8 @@ fn Path? Path.absolute(self, Allocator allocator)
 			return { string::from_wstring(allocator, buffer), WIN32, allocator };
 		};
 	$else
-		String cwd = os::getcwd(tmem())!;
-		return (Path){ cwd, self.env, tmem() }.append(allocator, path_str)!;
+		String cwd = os::getcwd(tmem)!;
+		return (Path){ cwd, self.env, tmem }.append(allocator, path_str)!;
 	$endif
 }
 
@@ -273,7 +273,7 @@ fn String? String.file_basename(self, Allocator allocator) => @pool()
 	return temp(self).basename().copy(allocator);
 }
 
-fn String? String.file_tbasename(self) => self.file_basename(tmem());
+fn String? String.file_tbasename(self) => self.file_basename(tmem);
 
 fn String Path.basename(self)
 {
@@ -283,7 +283,7 @@ fn String Path.basename(self)
 	return path_str[basename_start..];
 }
 
-fn String? String.path_tdirname(self) => self.path_dirname(tmem());
+fn String? String.path_tdirname(self) => self.path_dirname(tmem);
 
 fn String? String.path_dirname(self, Allocator allocator) => @pool()
 {
@@ -347,7 +347,7 @@ fn Path? String.to_path(self, Allocator allocator)
 
 fn Path? String.to_tpath(self)
 {
-	return new(tmem(), self);
+	return new(tmem, self);
 }
 
 fn usz? volume_name_len(String path, PathEnv path_env) @local
diff --git a/lib/std/io/stream/bytebuffer.c3 b/lib/std/io/stream/bytebuffer.c3
index 3e4c9b6e8..3e086314d 100644
--- a/lib/std/io/stream/bytebuffer.c3
+++ b/lib/std/io/stream/bytebuffer.c3
@@ -26,7 +26,7 @@ fn ByteBuffer* ByteBuffer.init(&self, Allocator allocator, usz max_read, usz ini
 
 fn ByteBuffer* ByteBuffer.tinit(&self, usz max_read, usz initial_capacity = 16)
 {
-	return self.init(tmem(), max_read, initial_capacity);
+	return self.init(tmem, max_read, initial_capacity);
 }
 
 <*
diff --git a/lib/std/io/stream/bytewriter.c3 b/lib/std/io/stream/bytewriter.c3
index a6a4c73a7..8a87e506c 100644
--- a/lib/std/io/stream/bytewriter.c3
+++ b/lib/std/io/stream/bytewriter.c3
@@ -27,7 +27,7 @@ fn ByteWriter* ByteWriter.init(&self, Allocator allocator)
 *>
 fn ByteWriter* ByteWriter.tinit(&self)
 {
-	return self.init(tmem()) @inline;
+	return self.init(tmem) @inline;
 }
 
 fn ByteWriter* ByteWriter.init_with_buffer(&self, char[] data)
diff --git a/lib/std/io/stream/multireader.c3 b/lib/std/io/stream/multireader.c3
index 3aaf5b855..e1d00a3a3 100644
--- a/lib/std/io/stream/multireader.c3
+++ b/lib/std/io/stream/multireader.c3
@@ -33,7 +33,7 @@ fn MultiReader* MultiReader.init(&self, Allocator allocator, InStream... readers
 *>
 fn MultiReader* MultiReader.tinit(&self, InStream... readers)
 {
-	return self.init(tmem(), ...readers);
+	return self.init(tmem, ...readers);
 }
 
 fn void MultiReader.free(&self)
diff --git a/lib/std/io/stream/multiwriter.c3 b/lib/std/io/stream/multiwriter.c3
index 793f4a26d..22c35c4bf 100644
--- a/lib/std/io/stream/multiwriter.c3
+++ b/lib/std/io/stream/multiwriter.c3
@@ -30,7 +30,7 @@ fn MultiWriter* MultiWriter.init(&self, Allocator allocator, OutStream... writer
 *>
 fn MultiWriter* MultiWriter.tinit(&self, OutStream... writers)
 {
-	return self.init(tmem(), ...writers);
+	return self.init(tmem, ...writers);
 }
 
 fn void MultiWriter.free(&self)
diff --git a/lib/std/net/inetaddr.c3 b/lib/std/net/inetaddr.c3
index f2cf5bce0..96f7c2977 100644
--- a/lib/std/net/inetaddr.c3
+++ b/lib/std/net/inetaddr.c3
@@ -63,7 +63,7 @@ fn String InetAddress.to_string(&self, Allocator allocator)
 
 fn String InetAddress.to_tstring(&self)
 {
-	return string::format(tmem(), "%s", *self);
+	return string::format(tmem, "%s", *self);
 }
 
 fn InetAddress? ipv6_from_str(String s)
diff --git a/lib/std/net/url.c3 b/lib/std/net/url.c3
index a3419df5e..365db081d 100644
--- a/lib/std/net/url.c3
+++ b/lib/std/net/url.c3
@@ -47,7 +47,7 @@ struct Url(Printable)
  @require url_string.len > 0 : "the url_string must be len 1 or more"
  @return "the parsed Url"
 *>
-fn Url? tparse(String url_string) => parse(tmem(), url_string);
+fn Url? tparse(String url_string) => parse(tmem, url_string);
 
 <*
  Parse a URL string into a Url struct.
@@ -252,7 +252,7 @@ struct UrlQueryValues
  @param [in] query
  @return "a UrlQueryValues HashMap"
 *>
-fn UrlQueryValues parse_query_to_temp(String query) => parse_query(tmem(), query);
+fn UrlQueryValues parse_query_to_temp(String query) => parse_query(tmem, query);
 
 <*
  Parse the query parameters of the Url into a UrlQueryValues map.
diff --git a/lib/std/net/url_encoding.c3 b/lib/std/net/url_encoding.c3
index 90c6156fa..815ea1299 100644
--- a/lib/std/net/url_encoding.c3
+++ b/lib/std/net/url_encoding.c3
@@ -100,7 +100,7 @@ fn String encode(Allocator allocator, String s, UrlEncodingMode mode) => @pool()
  @param mode : "Url encoding mode"
  @return "Percent-encoded String"
 *>
-fn String tencode(String s, UrlEncodingMode mode) => encode(tmem(), s, mode);
+fn String tencode(String s, UrlEncodingMode mode) => encode(tmem, s, mode);
 
 <*
  Calculate the length of the percent-decoded string.
@@ -167,4 +167,4 @@ fn String? decode(Allocator allocator, String s, UrlEncodingMode  mode) => @pool
  @param mode : "Url encoding mode"
  @return "Percent-decoded String"
 *>
-fn String? tdecode(String s, UrlEncodingMode  mode) => decode(tmem(), s, mode);
+fn String? tdecode(String s, UrlEncodingMode  mode) => decode(tmem, s, mode);
diff --git a/lib/std/os/env.c3 b/lib/std/os/env.c3
index 4a40d6b49..525d09049 100644
--- a/lib/std/os/env.c3
+++ b/lib/std/os/env.c3
@@ -36,7 +36,7 @@ fn String? get_var(Allocator allocator, String name) => @pool()
 
 fn String? tget_var(String name)
 {
-	return get_var(tmem(), name);
+	return get_var(tmem, name);
 }
 
 <*
diff --git a/lib/std/os/macos/darwin.c3 b/lib/std/os/macos/darwin.c3
index 59e081843..3c136662f 100644
--- a/lib/std/os/macos/darwin.c3
+++ b/lib/std/os/macos/darwin.c3
@@ -80,7 +80,7 @@ fn uptr? load_address() @local
 {
 	Darwin_segment_command_64* cmd = darwin::getsegbyname("__TEXT");
 	if (!cmd) return backtrace::SEGMENT_NOT_FOUND?;
-	String path = env::executable_path(tmem()) ?? backtrace::EXECUTABLE_PATH_NOT_FOUND?!;
+	String path = env::executable_path(tmem) ?? backtrace::EXECUTABLE_PATH_NOT_FOUND?!;
 	uint dyld_count = darwin::_dyld_image_count();
 	for (uint i = 0; i < dyld_count; i++)
 	{
@@ -147,7 +147,7 @@ fn BacktraceList? symbolize_backtrace(Allocator allocator, void*[] backtrace)
 	}
 	@pool()
 	{
-		String execpath = executable_path(tmem())!;
+		String execpath = executable_path(tmem)!;
 		foreach (addr : backtrace)
 		{
 			list.push(backtrace_load_element(allocator, execpath, addr, load_addr) ?? backtrace::BACKTRACE_UNKNOWN);
diff --git a/lib/std/threads/thread.c3 b/lib/std/threads/thread.c3
index a030da9f6..47e673de7 100644
--- a/lib/std/threads/thread.c3
+++ b/lib/std/threads/thread.c3
@@ -72,7 +72,11 @@ macro void OnceFlag.call(&flag, OnceFn func) => NativeOnceFlag.call_once((Native
 
 macro void yield() => os::native_thread_yield();
 macro Thread current() => (Thread)os::native_thread_current();
-macro void exit(int result) => os::native_thread_exit(result);
+macro void exit(int result)
+{
+	allocator::destroy_temp_allocators();
+	os::native_thread_exit(result);
+}
 macro void? sleep(Duration d) @maydiscard => os::native_sleep_nano(d.to_nano());
 macro void? sleep_ms(ulong ms) @maydiscard  => sleep(time::ms(ms));
 macro void? sleep_ns(NanoDuration ns) @maydiscard  => os::native_sleep_nano(ns);
diff --git a/lib/std/time/format.c3 b/lib/std/time/format.c3
index 41ec56b6f..31a05af70 100644
--- a/lib/std/time/format.c3
+++ b/lib/std/time/format.c3
@@ -62,7 +62,7 @@ fn String format(Allocator allocator, DateTimeFormat type, TzDateTime dt)
 	}
 }
 
-fn String tformat(DateTimeFormat dt_format, TzDateTime dt) => format(tmem(), dt_format, dt);
+fn String tformat(DateTimeFormat dt_format, TzDateTime dt) => format(tmem, dt_format, dt);
 
 fn String TzDateTime.format(self, Allocator allocator, DateTimeFormat dt_format) => format(allocator, dt_format, self);
 
diff --git a/releasenotes.md b/releasenotes.md
index 96210899f..054569744 100644
--- a/releasenotes.md
+++ b/releasenotes.md
@@ -40,6 +40,8 @@
 - Temp allocator now supports more than 2 in-flight stacks.
 - Printing stacktrace uses its own temp allocator.
 - Allow inferred type on body parameters. E.g. `@stack_mem(1024; alloc) { ... };`
+- Use `@pool_init()` to set up a temp pool on a thread. Only the main thread has implicit temp pool setup.
+- `tmem` is now a variable.
 
 ### Fixes
 - Fix address sanitizer to work on MachO targets (e.g. MacOS).
diff --git a/resources/testfragments/allocators_testing.c3 b/resources/testfragments/allocators_testing.c3
index bb33fd161..60fc088f8 100644
--- a/resources/testfragments/allocators_testing.c3
+++ b/resources/testfragments/allocators_testing.c3
@@ -9,7 +9,7 @@ enum Foo
 
 fn void print_pages()
 {
-	tmem().print_pages(io::stdout())!!;
+	tmem.print_pages(io::stdout())!!;
 }
 
 fn void setstring(char* dst, String str)
@@ -63,7 +63,7 @@ fn void main()
 	io::printf("First big: %p\n", first_big);
 	print_pages();
 	};
-	mem::@scoped(tmem())
+	mem::@scoped(tmem)
 	{
 		io::printf("Malloc: %p\n", (void*)malloc(23));
 		io::printf("Malloc: %p\n", (void*)malloc(23));
@@ -73,8 +73,8 @@ fn void main()
 	{
 		io::printf("Talloc: %p\n", (void*)tmalloc(22));
 	};
-	testAllocator(tmem(), 126);
-	testAllocator(tmem(), 12600);
+	testAllocator(tmem, 126);
+	testAllocator(tmem, 12600);
 	ArenaAllocator aa;
 	aa.init(&&char[1024] {});
 	testAllocator(&aa, 126);
diff --git a/test/src/test_suite_runner.c3 b/test/src/test_suite_runner.c3
index 96437346d..23acb7167 100644
--- a/test/src/test_suite_runner.c3
+++ b/test/src/test_suite_runner.c3
@@ -476,7 +476,7 @@ fn void test_file(Path file_path)
     		io::printfn(`FAILED - %s did not contain: "%s"`, file.name, next);
     		io::printfn("\n\n\n---------------------------------------------------> %s\n\n", file.name);
     		(void)file_ll.seek(0);
-    		(void)io::printn((String)io::read_fully(tmem(), &file_ll));
+    		(void)io::printn((String)io::read_fully(tmem, &file_ll));
     		io::printfn("<---------------------------------------------------- %s\n", file_path);
     		return;
     	}
@@ -496,7 +496,7 @@ fn void test_file(Path file_path)
 fn void? test_path(Path file_path)
 {
 	(void)path::chdir(start_cwd);
-	foreach (file : path::ls(tmem(), file_path)!!)
+	foreach (file : path::ls(tmem, file_path)!!)
 	{
 		@pool()
 		{
diff --git a/test/test_suite/generic/generic_lambda_complex.c3t b/test/test_suite/generic/generic_lambda_complex.c3t
index a08951b7d..760c6e37a 100644
--- a/test/test_suite/generic/generic_lambda_complex.c3t
+++ b/test/test_suite/generic/generic_lambda_complex.c3t
@@ -171,79 +171,62 @@ entry:
   %ft = alloca %TextTemplate, align 8
   %error_var = alloca i64, align 8
   %indirectarg = alloca %"char[]", align 8
-  %indirectarg1 = alloca %any, align 8
   %varargslots = alloca [1 x %any], align 16
-  %indirectarg2 = alloca %"any[]", align 8
-  %error_var3 = alloca i64, align 8
-  %varargslots8 = alloca [1 x %any], align 16
-  %indirectarg10 = alloca %"any[]", align 8
+  %indirectarg1 = alloca %"any[]", align 8
+  %error_var2 = alloca i64, align 8
+  %varargslots7 = alloca [1 x %any], align 16
+  %indirectarg9 = alloca %"any[]", align 8
   store %"char[]" { ptr @.str, i64 21 }, ptr %foo_tmpl, align 8
   call void @llvm.memset.p0.i64(ptr align 8 %ft, i8 0, i64 72, i1 false)
-  %0 = load ptr, ptr @std.core.mem.allocator.current_temp, align 8
-  %i2b = icmp ne ptr %0, null
-  br i1 %i2b, label %cond.lhs, label %cond.rhs
-
-cond.lhs:                                         ; preds = %entry
-  br label %cond.phi
-
-cond.rhs:                                         ; preds = %entry
-  %1 = call ptr @std.core.mem.allocator.create_temp_allocator()
-  br label %cond.phi
-
-cond.phi:                                         ; preds = %cond.rhs, %cond.lhs
-  %val = phi ptr [ %0, %cond.lhs ], [ %1, %cond.rhs ]
-  %2 = insertvalue %any undef, ptr %val, 0
-  %3 = insertvalue %any %2, i64 ptrtoint (ptr @"$ct.std.core.mem.allocator.TempAllocator" to i64), 1
   %lo = load ptr, ptr %foo_tmpl, align 8
   %ptradd = getelementptr inbounds i8, ptr %foo_tmpl, i64 8
   %hi = load i64, ptr %ptradd, align 8
   store %"char[]" { ptr @.str.2, i64 2 }, ptr %indirectarg, align 8
-  store %any %3, ptr %indirectarg1, align 8
-  %4 = call i64 @"abc$text_test.Foo$.TextTemplate.init"(ptr %ft, ptr %lo, i64 %hi, ptr @.str.1, i64 2, ptr byval(%"char[]") align 8 %indirectarg, ptr byval(%any) align 8 %indirectarg1)
-  %not_err = icmp eq i64 %4, 0
-  %5 = call i1 @llvm.expect.i1(i1 %not_err, i1 true)
-  br i1 %5, label %after_check, label %assign_optional
+  %0 = call i64 @"abc$text_test.Foo$.TextTemplate.init"(ptr %ft, ptr %lo, i64 %hi, ptr @.str.1, i64 2, ptr byval(%"char[]") align 8 %indirectarg, ptr byval(%any) align 8 @std.core.mem.allocator.current_temp)
+  %not_err = icmp eq i64 %0, 0
+  %1 = call i1 @llvm.expect.i1(i1 %not_err, i1 true)
+  br i1 %1, label %after_check, label %assign_optional
 
-assign_optional:                                  ; preds = %cond.phi
-  store i64 %4, ptr %error_var, align 8
+assign_optional:                                  ; preds = %entry
+  store i64 %0, ptr %error_var, align 8
   br label %panic_block
 
-after_check:                                      ; preds = %cond.phi
+after_check:                                      ; preds = %entry
   br label %noerr_block
 
 panic_block:                                      ; preds = %assign_optional
-  %6 = insertvalue %any undef, ptr %error_var, 0
-  %7 = insertvalue %any %6, i64 ptrtoint (ptr @"$ct.fault" to i64), 1
-  store %any %7, ptr %varargslots, align 16
-  %8 = insertvalue %"any[]" undef, ptr %varargslots, 0
-  %"$$temp" = insertvalue %"any[]" %8, i64 1, 1
-  store %"any[]" %"$$temp", ptr %indirectarg2, align 8
-  call void @std.core.builtin.panicf(ptr @.panic_msg, i64 36, ptr @.file
+  %2 = insertvalue %any undef, ptr %error_var, 0
+  %3 = insertvalue %any %2, i64 ptrtoint (ptr @"$ct.fault" to i64), 1
+  store %any %3, ptr %varargslots, align 16
+  %4 = insertvalue %"any[]" undef, ptr %varargslots, 0
+  %"$$temp" = insertvalue %"any[]" %4, i64 1, 1
+  store %"any[]" %"$$temp", ptr %indirectarg1, align 8
+  call void @std.core.builtin.panicf(ptr @.panic_msg, i64 36, ptr @.file, i64 25, ptr @.func, i64 4, i32 159, ptr byval(%"any[]") align 8 %indirectarg1) #3
   unreachable
 
 noerr_block:                                      ; preds = %after_check
-  %9 = call i64 @"abc$text_test.Foo$.TextTemplate.free"(ptr %ft)
-  %not_err4 = icmp eq i64 %9, 0
-  %10 = call i1 @llvm.expect.i1(i1 %not_err4, i1 true)
-  br i1 %10, label %after_check6, label %assign_optional5
+  %5 = call i64 @"abc$text_test.Foo$.TextTemplate.free"(ptr %ft)
+  %not_err3 = icmp eq i64 %5, 0
+  %6 = call i1 @llvm.expect.i1(i1 %not_err3, i1 true)
+  br i1 %6, label %after_check5, label %assign_optional4
 
-assign_optional5:                                 ; preds = %noerr_block
-  store i64 %9, ptr %error_var3, align 8
-  br label %panic_block7
+assign_optional4:                                 ; preds = %noerr_block
+  store i64 %5, ptr %error_var2, align 8
+  br label %panic_block6
 
-after_check6:                                     ; preds = %noerr_block
-  br label %noerr_block11
+after_check5:                                     ; preds = %noerr_block
+  br label %noerr_block10
 
-panic_block7:                                     ; preds = %assign_optional5
-  %11 = insertvalue %any undef, ptr %error_var3, 0
-  %12 = insertvalue %any %11, i64 ptrtoint (ptr @"$ct.fault" to i64), 1
-  store %any %12, ptr %varargslots8, align 16
-  %13 = insertvalue %"any[]" undef, ptr %varargslots8, 0
-  %"$$temp9" = insertvalue %"any[]" %13, i64 1, 1
-  store %"any[]" %"$$temp9", ptr %indirectarg10, align 8
-  call void @std.core.builtin.panicf(ptr @.panic_msg, i64 36, ptr @.file, i64 25, ptr @.func,
+panic_block6:                                     ; preds = %assign_optional4
+  %7 = insertvalue %any undef, ptr %error_var2, 0
+  %8 = insertvalue %any %7, i64 ptrtoint (ptr @"$ct.fault" to i64), 1
+  store %any %8, ptr %varargslots7, align 16
+  %9 = insertvalue %"any[]" undef, ptr %varargslots7, 0
+  %"$$temp8" = insertvalue %"any[]" %9, i64 1, 1
+  store %"any[]" %"$$temp8", ptr %indirectarg9, align 8
+  call void @std.core.builtin.panicf(ptr @.panic_msg, i64 36, ptr @.file, i64 25, ptr @.func, i64 4, i32 160, ptr byval(%"any[]") align 8 %indirectarg9) #3
   unreachable
 
-noerr_block11:                                    ; preds = %after_check6
+noerr_block10:                                    ; preds = %after_check5
   ret void
 }
diff --git a/test/unit/stdlib/mem/temp_mem.c3 b/test/unit/stdlib/mem/temp_mem.c3
index 69d58a211..d6a2d840f 100644
--- a/test/unit/stdlib/mem/temp_mem.c3
+++ b/test/unit/stdlib/mem/temp_mem.c3
@@ -18,7 +18,7 @@ fn String breakit(String s, Allocator a)
 {
     @pool()
     {
-        return inner2("foo".concat(tmem(), s), a);
+        return inner2("foo".concat(tmem, s), a);
     };
 }
 
@@ -52,7 +52,7 @@ fn String inner4(String s, Allocator a)
 {
     @pool()
     {
-        String y = s.concat(tmem(), "xy**********").copy(a);
+        String y = s.concat(tmem, "xy**********").copy(a);
         return y;
     };
 }