diff --git a/include/meson.build b/include/meson.build
index 56f9c8e..a31fae5 100644
--- a/include/meson.build
+++ b/include/meson.build
@@ -2,6 +2,7 @@
 
 install_headers(
   'stdplus/cancel.hpp',
+  'stdplus/concepts.hpp',
   'stdplus/exception.hpp',
   'stdplus/flags.hpp',
   'stdplus/handle/copyable.hpp',
diff --git a/include/stdplus/concepts.hpp b/include/stdplus/concepts.hpp
new file mode 100644
index 0000000..41373f6
--- /dev/null
+++ b/include/stdplus/concepts.hpp
@@ -0,0 +1,25 @@
+#pragma once
+#include <concepts>
+#include <type_traits>
+
+namespace stdplus
+{
+
+template <typename T, typename U>
+concept WeaklyEqualityComparableWith = requires(
+    const std::remove_reference_t<T>& t, const std::remove_reference_t<U>& u) {
+                                           {
+                                               t == u
+                                           } -> std::convertible_to<bool>;
+                                           {
+                                               t != u
+                                           } -> std::convertible_to<bool>;
+                                           {
+                                               u == t
+                                           } -> std::convertible_to<bool>;
+                                           {
+                                               u != t
+                                           } -> std::convertible_to<bool>;
+                                       };
+
+}