utils: Add scope_exit object

This is a utility for RAII-style operations. An object that will run
code when a scope is left.

Also includes unit tests.

2 files changed, 46 insertions, 0 deletions

diff --git a/host/tests/CMakeLists.txt b/host/tests/CMakeLists.txt
index 8a67e3f85..33fbcdbf9 100644
--- a/host/tests/CMakeLists.txt
+++ b/host/tests/CMakeLists.txt
@@ -39,6 +39,7 @@ set(test_sources
     narrow_cast_test.cpp
     property_test.cpp
     ranges_test.cpp
+    scope_exit_test.cpp
     sid_t_test.cpp
     sensors_test.cpp
     soft_reg_test.cpp
diff --git a/host/tests/scope_exit_test.cpp b/host/tests/scope_exit_test.cpp
new file mode 100644
index 000000000..7c05613a8
--- /dev/null
+++ b/host/tests/scope_exit_test.cpp
@@ -0,0 +1,45 @@
+//
+// Copyright 2019 Ettus Research, a National Instruments Brand
+//
+// SPDX-License-Identifier: GPL-3.0-or-later
+//
+
+#include <uhd/utils/scope_exit.hpp>
+#include <boost/test/unit_test.hpp>
+#include <iostream>
+
+BOOST_AUTO_TEST_CASE(test_scope_exit)
+{
+    bool flag = false;
+    {
+        auto flag_setter = uhd::utils::scope_exit::make([&flag]() { flag = true; });
+        BOOST_CHECK(!flag);
+    }
+    BOOST_CHECK(flag);
+}
+
+BOOST_AUTO_TEST_CASE(test_scope_exit_function_object)
+{
+    bool flag = false;
+    std::function<void(void)> resetter = [&flag]() { flag = true; };
+
+    {
+        auto flag_setter = uhd::utils::scope_exit::make(std::move(resetter));
+        BOOST_CHECK(!flag);
+    }
+    BOOST_CHECK(flag);
+}
+
+BOOST_AUTO_TEST_CASE(test_scope_exit_function_named_lambda)
+{
+    bool flag = false;
+    auto resetter = [&flag]() { flag = true; };
+
+    {
+        // Note: Does not require std::move()
+        auto flag_setter = uhd::utils::scope_exit::make(resetter);
+        BOOST_CHECK(!flag);
+    }
+    BOOST_CHECK(flag);
+}
+