From 57c783d2c95df136fe1ad2c26d5768ffe6bc8f6e Mon Sep 17 00:00:00 2001
From: Alex Guteniev <gutenev@gmail.com>
Date: Sun, 26 Oct 2025 10:20:49 +0200
Subject: [PATCH] `move_only_function`: eliminate the repeated part in call
 specializations

---
 stl/inc/functional                            | 26 ++-----------------
 .../move_only_function_specializations.py     |  4 +--
 2 files changed, 3 insertions(+), 27 deletions(-)

diff --git a/stl/inc/functional b/stl/inc/functional
index 48feddd89c4..4a7e25a9f15 100644
--- a/stl/inc/functional
+++ b/stl/inc/functional
@@ -1535,6 +1535,8 @@ _NODISCARD void* _Function_new_large(_CTypes&&... _Args) {
 template <class _Rx, bool _Noexcept, class... _Types>
 class _Move_only_function_base {
 public:
+    using result_type = _Rx;
+
     // TRANSITION, DevCom-1208330: use noexcept(_Noexcept) instead
     template <bool>
     struct _Invoke_t {
@@ -1730,8 +1732,6 @@ class _Move_only_function_call {
 template <class _Rx, class... _Types>
 class _Move_only_function_call<_Rx(_Types...)> : public _Move_only_function_base<_Rx, false, _Types...> {
 public:
-    using result_type = _Rx;
-
     template <class _Vt>
     using _VtInvQuals = _Vt&;
 
@@ -1747,8 +1747,6 @@ public:
 template <class _Rx, class... _Types>
 class _Move_only_function_call<_Rx(_Types...) &> : public _Move_only_function_base<_Rx, false, _Types...> {
 public:
-    using result_type = _Rx;
-
     template <class _Vt>
     using _VtInvQuals = _Vt&;
 
@@ -1763,8 +1761,6 @@ public:
 template <class _Rx, class... _Types>
 class _Move_only_function_call<_Rx(_Types...) &&> : public _Move_only_function_base<_Rx, false, _Types...> {
 public:
-    using result_type = _Rx;
-
     template <class _Vt>
     using _VtInvQuals = _Vt&&;
 
@@ -1779,8 +1775,6 @@ public:
 template <class _Rx, class... _Types>
 class _Move_only_function_call<_Rx(_Types...) const> : public _Move_only_function_base<_Rx, false, _Types...> {
 public:
-    using result_type = _Rx;
-
     template <class _Vt>
     using _VtInvQuals = const _Vt&;
 
@@ -1796,8 +1790,6 @@ public:
 template <class _Rx, class... _Types>
 class _Move_only_function_call<_Rx(_Types...) const&> : public _Move_only_function_base<_Rx, false, _Types...> {
 public:
-    using result_type = _Rx;
-
     template <class _Vt>
     using _VtInvQuals = const _Vt&;
 
@@ -1812,8 +1804,6 @@ public:
 template <class _Rx, class... _Types>
 class _Move_only_function_call<_Rx(_Types...) const&&> : public _Move_only_function_base<_Rx, false, _Types...> {
 public:
-    using result_type = _Rx;
-
     template <class _Vt>
     using _VtInvQuals = const _Vt&&;
 
@@ -1829,8 +1819,6 @@ public:
 template <class _Rx, class... _Types>
 class _Move_only_function_call<_Rx(_Types...) noexcept> : public _Move_only_function_base<_Rx, true, _Types...> {
 public:
-    using result_type = _Rx;
-
     template <class _Vt>
     using _VtInvQuals = _Vt&;
 
@@ -1846,8 +1834,6 @@ public:
 template <class _Rx, class... _Types>
 class _Move_only_function_call<_Rx(_Types...) & noexcept> : public _Move_only_function_base<_Rx, true, _Types...> {
 public:
-    using result_type = _Rx;
-
     template <class _Vt>
     using _VtInvQuals = _Vt&;
 
@@ -1862,8 +1848,6 @@ public:
 template <class _Rx, class... _Types>
 class _Move_only_function_call<_Rx(_Types...) && noexcept> : public _Move_only_function_base<_Rx, true, _Types...> {
 public:
-    using result_type = _Rx;
-
     template <class _Vt>
     using _VtInvQuals = _Vt&&;
 
@@ -1878,8 +1862,6 @@ public:
 template <class _Rx, class... _Types>
 class _Move_only_function_call<_Rx(_Types...) const noexcept> : public _Move_only_function_base<_Rx, true, _Types...> {
 public:
-    using result_type = _Rx;
-
     template <class _Vt>
     using _VtInvQuals = const _Vt&;
 
@@ -1896,8 +1878,6 @@ template <class _Rx, class... _Types>
 class _Move_only_function_call<_Rx(_Types...) const & noexcept>
     : public _Move_only_function_base<_Rx, true, _Types...> {
 public:
-    using result_type = _Rx;
-
     template <class _Vt>
     using _VtInvQuals = const _Vt&;
 
@@ -1913,8 +1893,6 @@ template <class _Rx, class... _Types>
 class _Move_only_function_call<_Rx(_Types...) const && noexcept>
     : public _Move_only_function_base<_Rx, true, _Types...> {
 public:
-    using result_type = _Rx;
-
     template <class _Vt>
     using _VtInvQuals = const _Vt&&;
 
diff --git a/tools/scripts/move_only_function_specializations.py b/tools/scripts/move_only_function_specializations.py
index 74ccbaa7475..548bf51486b 100644
--- a/tools/scripts/move_only_function_specializations.py
+++ b/tools/scripts/move_only_function_specializations.py
@@ -8,8 +8,6 @@ def specialization(cv: str, ref: str, ref_inv: str, noex: str, noex_val: str, ca
 class _Move_only_function_call<_Rx(_Types...) {cv} {ref} {noex}>
     : public _Move_only_function_base<_Rx, {noex_val}, _Types...> {{
 public:
-    using result_type = _Rx;
-
     template <class _Vt>
     using _VtInvQuals = {cv} _Vt {ref_inv};
 
@@ -39,4 +37,4 @@ def cvref_permutations(noex: str, noex_val: str, trait: str) -> str:
     print(cvref_permutations("", "false", "is_invocable_r_v") + "\n" \
         + "#ifdef __cpp_noexcept_function_type" + "\n" \
         + cvref_permutations("noexcept", "true", "is_nothrow_invocable_r_v") \
-        + "#endif // __cpp_noexcept_function_type")
+        + "#endif // defined(__cpp_noexcept_function_type)")