From: Kefu Chai <tchaikov@gmail.com>
Date: Sun, 21 Aug 2022 00:23:00 +0000 (+0800)
Subject: include/denc: redefine is_const_iterator
X-Git-Tag: v18.0.0~195^2~4
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=3fd12ff38ddfea869331bfec439307f2315ff11d;p=ceph.git

include/denc: redefine is_const_iterator

to just check for the return type of `it.get_pos_add(n)`, this
is exactly what we expect from a buffer::ptr::const_iterator.
it is more specific and less confusing.

Signed-off-by: Kefu Chai <tchaikov@gmail.com>
---

diff --git a/src/include/denc.h b/src/include/denc.h
index 96b7e7c099fc..b8982fa2110d 100644
--- a/src/include/denc.h
+++ b/src/include/denc.h
@@ -26,6 +26,7 @@
 
 #include <array>
 #include <cstring>
+#include <concepts>
 #include <map>
 #include <optional>
 #include <set>
@@ -283,8 +284,9 @@ using underlying_type_t = typename underlying_type<T>::type;
 }
 
 template<class It>
-concept is_const_iterator =
-std::is_const_v<std::remove_pointer_t<typename It::pointer>>;
+concept is_const_iterator = requires(It& it, size_t n) {
+  { it.get_pos_add(n) } -> std::same_as<const char*>;
+};
 
 template<typename T, is_const_iterator It>
 const T& get_pos_add(It& i) {