diff --git a/resources/lib/std/io.c3 b/resources/lib/std/io.c3
index e92568d84..9764463f4 100644
--- a/resources/lib/std/io.c3
+++ b/resources/lib/std/io.c3
@@ -1,4 +1,6 @@
 module std::io;
+import std::mem;
+import libc;
 
 errtype IoError
 {
@@ -54,6 +56,21 @@ func int println(char *message = "") @inline
     return _puts(message);
 }
 
+
+func 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)!!;
+
+    mem::copy(filename_copy, (char*)(filename), filename.len);
+    mem::copy(mode_copy, (char*)(mode), mode.len);
+    filename_copy[filename.len] = 0;
+    mode_copy[filename.len] = 0;
+    file.file = libc::fopen(filename_copy, mode_copy);
+    if (!file.file) return IoError.FILE_NOT_FOUND!;
+}
+
 /*
 
 enum Seek
@@ -73,11 +90,6 @@ func FileError errorFromErrno()
     return FileError { };
 }
 
-public func void! File.open(File *file, char *filename, char *mode)
-{
-    file.file = fopen(filename, mode);
-    if (!file.file) return errorFromErrno()!;
-}
 
 public func void! File.seek(File *file, long offset, Seek seekMode = Seek.SET)
 {
diff --git a/resources/lib/std/libc.c3 b/resources/lib/std/libc.c3
new file mode 100644
index 000000000..1e73f7895
--- /dev/null
+++ b/resources/lib/std/libc.c3
@@ -0,0 +1,167 @@
+module libc;
+
+// stdlib
+
+// Constants need to be per os/arch
+const int EXIT_FAILURE = 1;
+const int EXIT_SUCCESS = 0;
+const int RAND_MAX = 0x7fffffff;
+
+struct DivResult
+{
+    int quot;
+    int rem;
+}
+
+struct LongDivResult
+{
+    long quot;
+    long rem;
+}
+
+define TerminateFunction = func void();
+define CompareFunction = func int(void*, void*);
+extern func double atof(char* str);
+extern func long atol(char* str);
+extern func double strtod(char* str, char** endptr);
+extern func long strtol(char* str, char** endptr, int base);
+extern func ulong stroul(char* str, char** endptr, int base);
+extern func void abort();
+extern func void atexit(TerminateFunction f);
+extern func void exit(int status);
+extern func char* getenv(char* name);
+extern func int system(char* str);
+extern func void bsearch(void* key, void *base, usize items, usize size, CompareFunction compare);
+extern func void qsort(void* base, usize items, usize size, CompareFunction compare);
+extern func int abs(int x);
+extern func DivResult div(int numer, int denom);
+extern func long labs(long x);
+extern func LongDivResult ldiv(long number, long denom);
+extern func int rand();
+extern func void srand(uint seed);
+
+// MB functions omitted
+
+// string
+extern func void* memchr(void* str, int c, usize n);
+extern func int memcmp(void* str1, void* str2, usize n);
+extern func void* memcpy(void* dest, void* src, usize n);
+extern func void* memmove(void* dest, void* src, usize n);
+extern func void* memset(void* dest, usize n);
+extern func char* strcat(char* dest, char* src);
+extern func char* strncat(char* dest, char* src, usize n);
+extern func char* strchr(char* str, int c);
+extern func int strcmp(char* str1, char* str2);
+extern func int strncmp(char* str1, char* str2, usize n);
+extern func int strcoll(char* str1, char* str2);
+extern func char* strcpy(char* dst, char* src);
+extern func char* strncpy(char* dst, char* src, usize n);
+extern func usize strcspn(char* str1, char* str2);
+extern func char* strerror(int errnum);
+extern func usize strlen(char* str);
+extern func char* strpbrk(char* str1, char* str2);
+extern func usize strspn(char* str1, char* str2);
+extern func char* strstr(char* haystack, char* needle);
+extern func char* strtok(char* str, char* delim);
+extern func usize strxfrm(char* dest, char* src, usize n);
+
+// malloc
+extern func void* malloc(usize size);
+extern func void* calloc(usize count, usize size);
+extern func void* free(void*);
+extern func void* realloc(void* ptr, usize size);
+
+// stdio
+
+define Fpos = long;
+define CFile = void*;
+
+// The following needs to be set per arch+os
+// For now I have simply pulled the defaults from MacOS
+const int SEEK_SET = 0;
+const int SEEK_CUR = 1;
+const int SEEK_END = 2;
+const int _IOFBF = 0; // Fully buffered
+const int _IOLBF = 1; // Line buffered
+const int _IONBF = 2; // Unbuffered
+const int BUFSIZ = 1024;
+const int EOF = -1;
+const int FOPEN_MAX = 20;
+const int FILENAME_MAX = 1024;
+
+extern func int fclose(CFile stream);
+extern func void clearerr(CFile stream);
+extern func int feof(CFile stream);
+extern func int ferror(CFile stream);
+extern func int fflush(CFile stream);
+extern func int fgetpos(CFile stream, Fpos* pos);
+extern func CFile fopen(char* filename, char* mode);
+extern func usize fread(void* ptr, usize size, usize nmemb, CFile stream);
+extern func CFile freopen(char* filename, char* mode, CFile stream);
+extern func int fseek(CFile stream, long offset, int whence);
+extern func int fsetpos(CFile stream, Fpos* pos);
+extern func long ftell(CFile stream);
+extern func usize fwrite(void* ptr, usize size, usize nmemb, CFile stream);
+extern func int remove(char* filename);
+extern func int rename(char* old_name, char* new_name);
+extern func void rewind(CFile stream);
+extern func void setbuf(CFile stream, char* buffer);
+extern func void setvbuf(CFile stream, char* buffer, int mode, usize size);
+extern func CFile tmpnam(char* str);
+extern func int fprintf(CFile stream, char* format, ...);
+extern func int printf(char* format, ...);
+extern func int sprintf(char* str, char* format, ...);
+extern func int fscanf(CFile stream, char* format, ...);
+extern func int scanf(char* format, ...);
+extern func int sscanf(char* str, char* format, ...);
+extern func int fgetc(CFile stream);
+extern func char* fgets(char* str, int n, CFile stream);
+extern func int fputc(int c, CFile stream);
+extern func int getc(CFile stream);
+extern func int getchar();
+extern func int putc(char c, CFile stream);
+extern func int putchar(int c);
+extern func int puts(char* str);
+extern func int ungetc(int c, CFile stream);
+extern func void perror(char* str);
+
+// vsprintf vprintf not supported
+
+// time.h
+
+struct Tm
+{
+	int	tm_sec;		/* seconds after the minute [0-60] */
+	int	tm_min;		/* minutes after the hour [0-59] */
+	int	tm_hour;	/* hours since midnight [0-23] */
+	int	tm_mday;	/* day of the month [1-31] */
+	int	tm_mon;		/* months since January [0-11] */
+	int	tm_year;	/* years since 1900 */
+	int	tm_wday;	/* days since Sunday [0-6] */
+	int	tm_yday;	/* days since January 1 [0-365] */
+	int	tm_isdst;	/* Daylight Savings Time flag */
+	long tm_gmtoff;	/* offset from UTC in seconds */
+    char *tm_zone;	/* timezone abbreviation */
+}
+
+// Likely wrong, must be per platform.
+const CLOCKS_PER_SEC = 1000000;
+
+// Time also needs to be per platform
+define Time = long;
+define Clock = ulong;
+
+extern func char* asctime(Tm *timeptr);
+extern func Clock clock();
+extern func char* ctime(Time *timer);
+extern func double difftime(Time time1, Time time2);
+extern func Tm* gmtime(Time *timer);
+extern func Tm* localtime(Time *timer);
+extern func Time mktime(Tm *timeptr);
+extern func usize strftime(char* str, usize maxsize, char* format, Tm *timeptr);
+extern func Time time(Time *timer);
+
+// signal
+define SignalFunction = func void(int);
+extern func SignalFunction signal(int sig, SignalFunction fn);
+// Incomplete
\ No newline at end of file
diff --git a/resources/testfragments/toposort.c3 b/resources/testfragments/toposort.c3
index cdc22fb1e..44fa8dc7f 100644
--- a/resources/testfragments/toposort.c3
+++ b/resources/testfragments/toposort.c3
@@ -23,11 +23,10 @@ struct TopoList
 }
 
 
-public func void sort(InputPair[] pairs, uint elements)
+func void sort(InputPair[] pairs, uint elements)
 {
-    printf(.x = "fe");
     InputPair[] result = @array::make(InputPair, pairs.len);
-    TopoList* top = mem::calloc(TopoList.sizeof, elements);
+    TopoList* top = @array::make(TopoList, elements);
     for (int i = 0; i < pairs.len; i++)
     {
         InputPair pair = pairs[i];
@@ -71,7 +70,7 @@ public func void sort(InputPair[] pairs, uint elements)
     }
 }
 
-public func void main()
+func void main()
 {
     InputPair[10] pairs = {
         { 9, 2 },
diff --git a/src/compiler/compiler.c b/src/compiler/compiler.c
index 3fe57ab31..cfad04cbe 100644
--- a/src/compiler/compiler.c
+++ b/src/compiler/compiler.c
@@ -300,8 +300,8 @@ void compiler_compile(void)
 		vec_add(global_context.sources, strformat("%s/std/mem.c3", global_context.lib_dir));
 		vec_add(global_context.sources, strformat("%s/std/array.c3", global_context.lib_dir));
 		vec_add(global_context.sources, strformat("%s/std/math.c3", global_context.lib_dir));
+		vec_add(global_context.sources, strformat("%s/std/libc.c3", global_context.lib_dir));
 	}
-
 	bool has_error = false;
 	VECEACH(global_context.sources, i)
 	{
diff --git a/src/compiler/enums.h b/src/compiler/enums.h
index 5e2965952..88e198714 100644
--- a/src/compiler/enums.h
+++ b/src/compiler/enums.h
@@ -358,6 +358,7 @@ typedef enum
 	TOKEN_PLUS_ASSIGN,      // +=
 	TOKEN_PLUSPLUS,         // ++
 	TOKEN_RBRAPIPE,         // |}
+	TOKEN_QUESTQUEST,       // ??
 	TOKEN_SCOPE,            // ::
 	TOKEN_SHL,              // <<
 	TOKEN_SHR,              // >>
diff --git a/src/compiler/lexer.c b/src/compiler/lexer.c
index 9778682d0..06b12c9d3 100644
--- a/src/compiler/lexer.c
+++ b/src/compiler/lexer.c
@@ -1569,6 +1569,7 @@ static bool lexer_scan_token_inner(Lexer *lexer, LexMode mode)
 			                                                                                    TOKEN_BIT_XOR,
 			                                                                                    "^");
 		case '?':
+			if (match(lexer, '?')) return add_token(lexer, TOKEN_QUESTQUEST, "??");
 			return match(lexer, ':') ? add_token(lexer, TOKEN_ELVIS, "?:") : add_token(lexer, TOKEN_QUESTION, "?");
 		case '<':
 			if (match(lexer, '<'))
diff --git a/src/compiler/parse_expr.c b/src/compiler/parse_expr.c
index 34d6dcdf4..ceac89a0b 100644
--- a/src/compiler/parse_expr.c
+++ b/src/compiler/parse_expr.c
@@ -872,7 +872,10 @@ static Expr *parse_bangbang_expr(Context *context, Expr *left)
 static Expr *parse_else_expr(Context *context, Expr *left)
 {
 	Expr *else_expr = EXPR_NEW_TOKEN(EXPR_ELSE, context->tok);
-	advance_and_verify(context, TOKEN_ELSE);
+	if (!try_consume(context, TOKEN_ELSE))
+	{
+		advance_and_verify(context, TOKEN_QUESTQUEST);
+	}
 	else_expr->else_expr.expr = left;
 	switch (context->tok.type)
 	{
@@ -1371,6 +1374,7 @@ ParseRule rules[TOKEN_EOF + 1] = {
 
 		[TOKEN_ELSE] = { NULL, parse_else_expr, PREC_ELSE },
 		[TOKEN_QUESTION] = { NULL, parse_ternary_expr, PREC_TERNARY },
+		[TOKEN_QUESTQUEST] = { NULL, parse_else_expr, PREC_ELSE},
 		[TOKEN_ELVIS] = { NULL, parse_ternary_expr, PREC_TERNARY },
 		[TOKEN_PLUSPLUS] = { parse_unary_expr, parse_post_unary, PREC_CALL },
 		[TOKEN_MINUSMINUS] = { parse_unary_expr, parse_post_unary, PREC_CALL },
diff --git a/src/compiler/parse_stmt.c b/src/compiler/parse_stmt.c
index 0819ff28f..0e5ed15b7 100644
--- a/src/compiler/parse_stmt.c
+++ b/src/compiler/parse_stmt.c
@@ -1028,6 +1028,7 @@ Ast *parse_stmt(Context *context)
 		case TOKEN_ALIAS:
 		case TOKEN_AS:
 		case TOKEN_ELSE:
+		case TOKEN_QUESTQUEST:
 		case TOKEN_ENUM:
 		case TOKEN_FUNC:
 		case TOKEN_GENERIC:
diff --git a/src/compiler/sema_expr.c b/src/compiler/sema_expr.c
index 2c2e205d4..5a0648f12 100644
--- a/src/compiler/sema_expr.c
+++ b/src/compiler/sema_expr.c
@@ -1107,7 +1107,7 @@ static inline bool sema_check_invalid_body_arguments(Context *context, Expr *cal
 	return true;
 }
 
-static inline bool sema_expand_call_arguments(Context *context, Expr *call, Decl **params, Expr **args, unsigned func_param_count, bool variadic)
+static inline bool sema_expand_call_arguments(Context *context, CalledDecl *callee, Expr *call, Decl **params, Expr **args, unsigned func_param_count, bool variadic)
 {
 	unsigned num_args = vec_size(args);
 
@@ -1197,10 +1197,18 @@ static inline bool sema_expand_call_arguments(Context *context, Expr *call, Decl
 		if (actual_args[i]) continue;
 
 		// 17b. Set the init expression.
-		if (params[i]->var.init_expr)
+		Expr *init_expr = params[i]->var.init_expr;
+		if (init_expr)
 		{
-			assert(params[i]->var.init_expr->resolve_status == RESOLVE_DONE);
-			actual_args[i] = params[i]->var.init_expr;
+			if (callee->macro)
+			{
+				actual_args[i] = copy_expr(init_expr);
+			}
+			else
+			{
+				assert(init_expr->resolve_status == RESOLVE_DONE);
+				actual_args[i] = init_expr;
+			}
 			continue;
 		}
 
@@ -1273,7 +1281,7 @@ static inline bool sema_expr_analyse_call_invocation(Context *context, Expr *cal
 		func_param_count--;
 	}
 
-	if (!sema_expand_call_arguments(context, call, params, args, func_param_count, callee.variadic != VARIADIC_NONE)) return false;
+	if (!sema_expand_call_arguments(context, &callee, call, params, args, func_param_count, callee.variadic != VARIADIC_NONE)) return false;
 
 	args = call->call_expr.arguments;
 	num_args = vec_size(args);
diff --git a/src/compiler/tokens.c b/src/compiler/tokens.c
index d4f05ecef..8e9dd129b 100644
--- a/src/compiler/tokens.c
+++ b/src/compiler/tokens.c
@@ -112,6 +112,8 @@ const char *token_type_to_string(TokenType type)
 			return "+=";
 		case TOKEN_PLUSPLUS:
 			return "++";
+		case TOKEN_QUESTQUEST:
+			return "??";
 		case TOKEN_RBRAPIPE:
 			return "|}";
 		case TOKEN_SCOPE:
diff --git a/src/version.h b/src/version.h
index f59962f01..0e00edec7 100644
--- a/src/version.h
+++ b/src/version.h
@@ -1 +1 @@
-#define COMPILER_VERSION "A233"
\ No newline at end of file
+#define COMPILER_VERSION "A234"
\ No newline at end of file
diff --git a/test/src/tester.py b/test/src/tester.py
index ec8e3b330..45cba6be9 100644
--- a/test/src/tester.py
+++ b/test/src/tester.py
@@ -170,7 +170,7 @@ class Issues:
         lines = len(self.sourcefile.content)
         while self.line < lines:
             line = self.sourcefile.content[self.line].strip()
-            if line.startswith("// #"):
+            if line.startswith("// #") or line.startswith("/* #"):
                 self.parse_header_directive(line)
                 self.line += 1
                 continue
diff --git a/test/test_suite/errors/else_checks.c3t b/test/test_suite/errors/else_checks.c3t
index 4e565a43b..156eb3558 100644
--- a/test/test_suite/errors/else_checks.c3t
+++ b/test/test_suite/errors/else_checks.c3t
@@ -4,13 +4,14 @@ extern func int! testError();
 
 func void test()
 {
-    double x = (testError() + testError()) else 100;
-    double y = (1 << testError()) else 100;
-    double z = testError() >> 1 else 100;
-    double w = testError() * testError() else 100;
+
+    double x = (testError() + testError()) ?? 100;
+    double y = (1 << testError()) ?? 100;
+    double z = testError() >> 1 ?? 100;
+    double w = testError() * testError() ?? 100;
 }
 
-// #expect: else_checks.ll
+/* #expect: else_checks.ll
 
 ; Function Attrs: nounwind
 declare i64 @testError(i32*) #0