1 files changed, 41 insertions, 0 deletions
diff --git a/src/boost/libs/contract/example/features/check.cpp b/src/boost/libs/contract/example/features/check.cpp
new file mode 100644
index 00000000..36aa9da3
--- /dev/null
+++ b/src/boost/libs/contract/example/features/check.cpp
@@ -0,0 +1,41 @@
+
+// Copyright (C) 2008-2018 Lorenzo Caminiti
+// Distributed under the Boost Software License, Version 1.0 (see accompanying
+// file LICENSE_1_0.txt or a copy at http://www.boost.org/LICENSE_1_0.txt).
+// See: http://www.boost.org/doc/libs/release/libs/contract/doc/html/index.html
+
+#include <boost/contract.hpp>
+
+int gcd(int const a, int const b) {
+    int result;
+    boost::contract::check c = boost::contract::function()
+        .precondition([&] {
+            BOOST_CONTRACT_ASSERT(a > 0);
+            BOOST_CONTRACT_ASSERT(b > 0);
+        })
+        .postcondition([&] {
+            BOOST_CONTRACT_ASSERT(result <= a);
+            BOOST_CONTRACT_ASSERT(result <= b);
+        })
+    ;
+
+    int x = a, y = b;
+    while(x != y) {
+        if(x > y) x = x - y;
+        else y = y - x;
+    }
+    return result = x;
+}
+
+//[check
+int main() {
+    // Implementation checks (via nullary functor).
+    boost::contract::check c = [] {
+        BOOST_CONTRACT_ASSERT(gcd(12, 28) == 4);
+        BOOST_CONTRACT_ASSERT(gcd(4, 14) == 2);
+    };
+
+    return 0;
+}
+//]
+