From ee980ee32fb84f90cf5ea16369e7ae009ed2dee7 Mon Sep 17 00:00:00 2001
From: Avi Kivity <avi@scylladb.com>
Date: Sat, 19 Sep 2020 17:34:35 +0300
Subject: [PATCH] hashers: convert illegal contraint to static_assert

The constraint on on cryptopp_hasher<>::impl is illegal, since it's not
on the base template. Convert it to a static_assert.

We could have moved it to the base template, but that would have undone
the work to push all the implementation details in .cc and reduce #include
load.

Found by clang.
---
 hashers.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hashers.cc b/hashers.cc
index cf9f2f727d..015a9122e0 100644
--- a/hashers.cc
+++ b/hashers.cc
@@ -38,8 +38,8 @@ concept HashUpdater =
     };
 
 template <typename T, size_t size>
-requires HashUpdater<T>
 struct cryptopp_hasher<T, size>::impl {
+    static_assert(HashUpdater<T>);
     using impl_type = typename hasher_traits<T>::impl_type;
 
     impl_type hash{};