From 7501eefd878ade72d185eade1d23c29aacd40398 Mon Sep 17 00:00:00 2001
From: Christian Mazakas <christian.mazakas@gmail.com>
Date: Wed, 5 Oct 2022 13:29:48 -0700
Subject: [PATCH] Updated unordered flat container to use declval instead of
 allocator_traits as old versions of clang don't have is_always_equal

---
 include/boost/unordered/unordered_flat_map.hpp | 7 ++-----
 include/boost/unordered/unordered_flat_set.hpp | 7 ++-----
 2 files changed, 4 insertions(+), 10 deletions(-)

diff --git a/include/boost/unordered/unordered_flat_map.hpp b/include/boost/unordered/unordered_flat_map.hpp
index c58ba91a..5734e6c9 100644
--- a/include/boost/unordered/unordered_flat_map.hpp
+++ b/include/boost/unordered/unordered_flat_map.hpp
@@ -127,16 +127,13 @@ namespace boost {
         return *this;
       }
 
-      unordered_flat_map& operator=(unordered_flat_map&& other)
-        noexcept(std::allocator_traits<allocator_type>::is_always_equal::value&&
-            std::is_nothrow_move_assignable<hasher>::value&&
-              std::is_nothrow_move_assignable<key_equal>::value)
+      unordered_flat_map& operator=(unordered_flat_map&& other) noexcept(
+        noexcept(std::declval<table_type&>() = std::declval<table_type&&>()))
       {
         table_ = std::move(other.table_);
         return *this;
       }
 
-
       allocator_type get_allocator() const noexcept
       {
         return table_.get_allocator();
diff --git a/include/boost/unordered/unordered_flat_set.hpp b/include/boost/unordered/unordered_flat_set.hpp
index 12ffd982..7c586503 100644
--- a/include/boost/unordered/unordered_flat_set.hpp
+++ b/include/boost/unordered/unordered_flat_set.hpp
@@ -121,16 +121,13 @@ namespace boost {
         return *this;
       }
 
-      unordered_flat_set& operator=(unordered_flat_set&& other)
-        noexcept(std::allocator_traits<allocator_type>::is_always_equal::value&&
-            std::is_nothrow_move_assignable<hasher>::value&&
-              std::is_nothrow_move_assignable<key_equal>::value)
+      unordered_flat_set& operator=(unordered_flat_set&& other) noexcept(
+        noexcept(std::declval<table_type&>() = std::declval<table_type&&>()))
       {
         table_ = std::move(other.table_);
         return *this;
       }
 
-
       allocator_type get_allocator() const noexcept
       {
         return table_.get_allocator();