diff --git a/releasenotes.md b/releasenotes.md
index e7c75aab5..9cd57cfca 100644
--- a/releasenotes.md
+++ b/releasenotes.md
@@ -3,6 +3,8 @@
 ## 0.7.6 Change list
 
 ### Changes / improvements
+- Add lenof() compile time function #2439
+- Allow doc comments on individual struct members, faultdefs and enum values #2427.
 
 ### Fixes
 - Compiler assert with var x @noinit = 0 #2452
@@ -12,6 +14,8 @@
 - Inlining location when accessing #foo symbols.
 - Improve inlined-at when checking generic code.
 - Fix codegen bug in expressions like `foo(x()) ?? io::EOF?` causing irregular crashes.
+- Correctly silence "unsupported architecture" warning with `--quiet` #2465
+- Overloading &[] should be enough for foreach. #2466
 
 ### Stdlib changes
 - Added generic `InterfaceList` to store a list of values that implement a specific interface
@@ -56,7 +60,6 @@
 - `$defined(#hash)` will not check the internal expression, just that `#hash` exists. Use `$defined((void)#hash)` for the old behaviour.
 - Added optional macro arguments using `macro foo(int x = ...)` which can be checked using `$defined(x)`.
 - Add compile time ternary `$val ??? <expr> : <expr>`.
-- Allow doc comments on individual struct members, faultdefs and enum values #2427.
 
 ### Fixes
 - List.remove_at would incorrectly trigger ASAN.
@@ -115,8 +118,6 @@
 - Fix missing end of line when encountering errors in project creation.
 - Const enum methods are not being recognized. #2445
 - $defined returns an error when assigning a struct initializer with an incorrect type #2449
-- Correctly silence "unsupported architecture" warning with `--quiet` #2465
-- Overloading &[] should be enough for foreach. #2466
 
 ### Stdlib changes
 - Add `==` to `Pair`, `Triple` and TzDateTime. Add print to `Pair` and `Triple`.
diff --git a/src/compiler/compiler_internal.h b/src/compiler/compiler_internal.h
index aaa08edce..6b49e4fab 100644
--- a/src/compiler/compiler_internal.h
+++ b/src/compiler/compiler_internal.h
@@ -3713,6 +3713,7 @@ static inline void expr_set_span(Expr *expr, SourceSpan loc)
 		case EXPR_VECTOR_FROM_ARRAY:
 		case EXPR_ADDR_CONVERSION:
 		case EXPR_RECAST:
+		case EXPR_LENOF:
 			expr_set_span(expr->inner_expr, loc);
 			return;
 		case EXPR_EXPRESSION_LIST:
diff --git a/src/compiler/copying.c b/src/compiler/copying.c
index b6deefb2f..108ba3322 100644
--- a/src/compiler/copying.c
+++ b/src/compiler/copying.c
@@ -503,6 +503,7 @@ Expr *copy_expr(CopyStruct *c, Expr *source_expr)
 		case EXPR_RVALUE:
 		case EXPR_RECAST:
 		case EXPR_ADDR_CONVERSION:
+		case EXPR_LENOF:
 			MACRO_COPY_EXPR(expr->inner_expr);
 			return expr;
 		case EXPR_MAKE_ANY:
diff --git a/src/compiler/enums.h b/src/compiler/enums.h
index 441c33ec4..69a9f2460 100644
--- a/src/compiler/enums.h
+++ b/src/compiler/enums.h
@@ -781,6 +781,7 @@ typedef enum
 	EXPR_PTR_TO_INT,
 	EXPR_LAMBDA,
 	EXPR_LAST_FAULT,
+	EXPR_LENOF,
 	EXPR_MACRO_BLOCK,
 	EXPR_MACRO_BODY,
 	EXPR_MACRO_BODY_EXPANSION,
@@ -1227,6 +1228,7 @@ typedef enum
 	TOKEN_IF,
 	TOKEN_INLINE,
 	TOKEN_IMPORT,
+	TOKEN_LENOF,
 	TOKEN_MACRO,
 	TOKEN_MODULE,
 	TOKEN_NEXTCASE,
@@ -1719,5 +1721,5 @@ case TYPE_U8: case TYPE_U16: case TYPE_U32: case TYPE_U64: case TYPE_U128
 #define UNRESOLVED_EXPRS EXPR_TRY_UNRESOLVED: case EXPR_ACCESS_UNRESOLVED: \
 	case EXPR_CATCH_UNRESOLVED: case EXPR_UNRESOLVED_IDENTIFIER: case EXPR_CAST: \
 	case EXPR_TYPEID: case EXPR_EMBED: case EXPR_VASPLAT: case EXPR_OTHER_CONTEXT: \
-	case EXPR_IOTA_DECL: \
+	case EXPR_IOTA_DECL: case EXPR_LENOF: \
 	case EXPR_GENERIC_IDENT: case EXPR_COMPOUND_LITERAL: case EXPR_MACRO_BODY: case EXPR_CT_SUBSCRIPT
diff --git a/src/compiler/parse_expr.c b/src/compiler/parse_expr.c
index 8b0ed36f5..063f866df 100644
--- a/src/compiler/parse_expr.c
+++ b/src/compiler/parse_expr.c
@@ -1237,6 +1237,22 @@ static Expr *parse_ct_embed(ParseContext *c, Expr *left, SourceSpan lhs_start UN
 	return embed;
 }
 
+/**
+ * lenof ::= LENOF '(' expr ')'
+ * flat_path ::= expr ('.' primary) | '[' expr ']')*
+ */
+static Expr *parse_lenof(ParseContext *c, Expr *left, SourceSpan lhs_start UNUSED)
+{
+	ASSERT(!left && "Unexpected left hand side");
+	Expr *expr = EXPR_NEW_TOKEN(EXPR_LENOF);
+	advance(c);
+	CONSUME_OR_RET(TOKEN_LPAREN, poisoned_expr);
+	ASSIGN_EXPR_OR_RET(expr->inner_expr, parse_expr(c), poisoned_expr);
+	CONSUME_OR_RET(TOKEN_RPAREN, poisoned_expr);
+	RANGE_EXTEND_PREV(expr);
+	return expr;
+}
+
 /**
  * ct_call ::= (CT_ALIGNOF | CT_FEATURE | CT_EXTNAMEOF | CT_OFFSETOF | CT_NAMEOF | CT_QNAMEOF) '(' flat_path ')'
  * flat_path ::= expr ('.' primary) | '[' expr ']')*
@@ -2155,6 +2171,7 @@ ParseRule rules[TOKEN_EOF + 1] = {
 		[TOKEN_TRUE] = { parse_bool, NULL, PREC_NONE },
 		[TOKEN_FALSE] = { parse_bool, NULL, PREC_NONE },
 		[TOKEN_NULL] = { parse_null, NULL, PREC_NONE },
+		[TOKEN_LENOF] = { parse_lenof, NULL, PREC_NONE },
 		[TOKEN_INTEGER] = { parse_integer, NULL, PREC_NONE },
 		[TOKEN_BUILTIN] = { parse_builtin, NULL, PREC_NONE },
 		[TOKEN_CHAR_LITERAL] = { parse_char_lit, NULL, PREC_NONE },
diff --git a/src/compiler/parse_stmt.c b/src/compiler/parse_stmt.c
index 4d9218ce9..c51d5caa8 100644
--- a/src/compiler/parse_stmt.c
+++ b/src/compiler/parse_stmt.c
@@ -1409,6 +1409,7 @@ Ast *parse_stmt(ParseContext *c)
 		case TOKEN_CT_VAEXPR:
 		case TOKEN_FALSE:
 		case TOKEN_INTEGER:
+		case TOKEN_LENOF:
 		case TOKEN_LPAREN:
 		case TOKEN_MINUS:
 		case TOKEN_MINUSMINUS:
diff --git a/src/compiler/sema_expr.c b/src/compiler/sema_expr.c
index 5c9c887dd..a8dd32bf9 100644
--- a/src/compiler/sema_expr.c
+++ b/src/compiler/sema_expr.c
@@ -10404,6 +10404,34 @@ static inline bool sema_expr_analyse_ct_is_const(SemaContext *context, Expr *exp
 	expr_rewrite_const_bool(expr, type_bool, sema_cast_const(inner));
 	return true;
 }
+static bool sema_expr_analyse_lenof(SemaContext *context, Expr *expr, bool *missing_ref)
+{
+	Expr *inner = expr->inner_expr;
+	if (!sema_analyse_expr(context, inner)) return false;
+	Type *canonical = inner->type->canonical;
+	Decl *len = sema_find_untyped_operator(canonical, OVERLOAD_LEN, NULL);
+	if (len)
+	{
+		return sema_insert_method_call(context, expr, len, inner, NULL, false);
+	}
+	switch (canonical->type_kind)
+	{
+		case TYPE_ARRAY:
+		case TYPE_VECTOR:
+			expr_rewrite_const_int(expr, type_isz, canonical->array.len);
+			return true;
+		case TYPE_SLICE:
+			expr_rewrite_slice_len(expr, inner, type_isz);
+			return true;
+		default:
+			if (missing_ref)
+			{
+				*missing_ref = true;
+				return false;
+			}
+			RETURN_SEMA_ERROR(inner, "%s does support lenof()", type_quoted_error_string(inner->type));
+	}
+}
 
 static inline bool sema_expr_analyse_ct_defined(SemaContext *context, Expr *expr)
 {
@@ -10432,7 +10460,14 @@ static inline bool sema_expr_analyse_ct_defined(SemaContext *context, Expr *expr
 				active_context->call_env.in_no_eval = true;
 				main_expr = main_expr->expr_other_context.inner;
 				goto RETRY;
-		case EXPR_ACCESS_UNRESOLVED:
+		case EXPR_LENOF:
+				if (!sema_expr_analyse_lenof(active_context, main_expr, &failed))
+				{
+					if (!failed) goto FAIL;
+					success = false;
+				}
+				break;
+			case EXPR_ACCESS_UNRESOLVED:
 				if (!sema_expr_analyse_access(active_context, main_expr, &failed, CHECK_VALUE, false))
 				{
 					if (!failed) goto FAIL;
@@ -11053,6 +11088,8 @@ static inline bool sema_analyse_expr_dispatch(SemaContext *context, Expr *expr,
 		case EXPR_MAKE_SLICE:
 		case EXPR_CT_SUBSCRIPT:
 			UNREACHABLE
+		case EXPR_LENOF:
+			return sema_expr_analyse_lenof(context, expr, NULL);
 		case EXPR_IOTA_DECL:
 			return sema_expr_analyse_iota_decl(context, expr);
 		case EXPR_TWO:
@@ -11601,7 +11638,7 @@ IDENT_CHECK:;
 		case EXPR_INT_TO_FLOAT:
 		case EXPR_INT_TO_PTR:
 		case EXPR_PTR_TO_INT:
-
+		case EXPR_LENOF:
 		case EXPR_RETHROW:
 		case EXPR_RETVAL:
 		case EXPR_RVALUE:
diff --git a/src/compiler/tokens.c b/src/compiler/tokens.c
index f61003456..c28031274 100644
--- a/src/compiler/tokens.c
+++ b/src/compiler/tokens.c
@@ -235,6 +235,8 @@ const char *token_type_to_string(TokenType type)
 			return "interface";
 		case TOKEN_IMPORT:
 			return "import";
+		case TOKEN_LENOF:
+			return "lenof";
 		case TOKEN_MACRO:
 			return "macro";
 		case TOKEN_MODULE:
diff --git a/test/unit/regression/lenof.c3 b/test/unit/regression/lenof.c3
new file mode 100644
index 000000000..af1c16153
--- /dev/null
+++ b/test/unit/regression/lenof.c3
@@ -0,0 +1,20 @@
+module regression;
+import std;
+
+
+fn void lenof_test() @test
+{
+	List{int} l;
+	l.push(123);
+	l.push(222);
+	l.push(111);
+	test::eq(lenof(l), 3);
+	int[] x = { 1, 2 };
+	test::eq(lenof(x), 2);
+	l.push(111);
+	test::eq(lenof(l), 4);
+	assert(!$defined(lenof(1)));
+	assert($defined(lenof(x)));
+	int* zz;
+	assert(!$defined(lenof(zz)));
+}
\ No newline at end of file