From 4b5dd8da79281b4ecb19906c4c5efbd309ef4d87 Mon Sep 17 00:00:00 2001
From: subcrip <contact@subc.rip>
Date: Fri, 31 May 2024 10:00:27 +0800
Subject: [PATCH] Update include.hh

Signed-off-by: subcrip <contact@subc.rip>
---
 include.hh | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/include.hh b/include.hh
index 90ccb1e..b65c83f 100644
--- a/include.hh
+++ b/include.hh
@@ -429,6 +429,9 @@ istream& operator>>(istream& in, MLLd& num) {
 }
 
 // miscancellous
+#define functor(func) [&](auto&&... val) \
+noexcept(noexcept(func(std::forward<decltype(val)>(val)...))) -> decltype(auto) \
+{return func(std::forward<decltype(val)>(val)...);}
 template <typename Func, typename RandomIt> void sort_by_key(RandomIt first, RandomIt last, Func extractor) {
     std::sort(first, last, [&] (auto&& a, auto&& b) { return std::less<>()(extractor(a), extractor(b)); });
 }