From 2cded73813e288f7570bac082affe6be451e7e00 Mon Sep 17 00:00:00 2001
From: Jonathan Poelen <jonathan.poelen@gmail.com>
Date: Sun, 9 Nov 2025 02:07:47 +0100
Subject: [PATCH] optimize mp_remove_if

compiler |      gcc-15       |     clang-20
before   | 0:00.21s - 67308K | 0:00.51s - 137744K
after    | 0:00.21s - 66956K | 0:00.49s - 138492K

```cpp
template<class> using pred = mp_true;
template<class I, class L = mp_iota<I>> using test
  = mp_remove_if<L, pred>;

using r1 = mp_transform<test, mp_iota_c<120>>;
```
---
 include/boost/mp11/detail/mp_remove_if.hpp | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/include/boost/mp11/detail/mp_remove_if.hpp b/include/boost/mp11/detail/mp_remove_if.hpp
index 9687b4a..cafbf34 100644
--- a/include/boost/mp11/detail/mp_remove_if.hpp
+++ b/include/boost/mp11/detail/mp_remove_if.hpp
@@ -32,8 +32,7 @@ template<template<class...> class L, class... T, template<class...> class P> str
     template<class U> struct _f { using type = mp_if<P<U>, mp_list<>, mp_list<U>>; };
     using type = mp_append<L<>, typename _f<T>::type...>;
 #else
-    template<class U> using _f = mp_if<P<U>, mp_list<>, mp_list<U>>;
-    using type = mp_append<L<>, _f<T>...>;
+    using type = mp_append<L<>, mp_if<P<T>, mp_list<>, mp_list<T>>...>;
 #endif
 };