From fa4cebadcffd9112da4b13c7cc7ccf21e2bee887 Mon Sep 17 00:00:00 2001
From: MarcoFalke <falke.marco@gmail.com>
Date: Sun, 28 Feb 2021 16:38:19 +0100
Subject: [PATCH] util: Make Assume() usable as unary expression

---
 src/test/util_tests.cpp | 3 +++
 src/util/check.h        | 2 +-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/test/util_tests.cpp b/src/test/util_tests.cpp
index 5a46002a79..32db6d6c83 100644
--- a/src/test/util_tests.cpp
+++ b/src/test/util_tests.cpp
@@ -76,6 +76,9 @@ BOOST_AUTO_TEST_CASE(util_check)
     const int two = *Assert(p_two);
     Assert(two == 2);
     Assert(true);
+    // Check that Assume can be used as unary expression
+    const bool result{Assume(two == 2)};
+    Assert(result);
 }
 
 BOOST_AUTO_TEST_CASE(util_criticalsection)
diff --git a/src/util/check.h b/src/util/check.h
index bc62da3440..e60088a2c6 100644
--- a/src/util/check.h
+++ b/src/util/check.h
@@ -69,7 +69,7 @@ T get_pure_r_value(T&& val)
 #ifdef ABORT_ON_FAILED_ASSUME
 #define Assume(val) Assert(val)
 #else
-#define Assume(val) ((void)(val))
+#define Assume(val) ([&]() -> decltype(get_pure_r_value(val)) { auto&& check = (val); return std::forward<decltype(get_pure_r_value(val))>(check); }())
 #endif
 
 #endif // BITCOIN_UTIL_CHECK_H