test: rename test source file

tests/test_expect.cpp

@@ -0,0 +1,30 @@
+#define BOOST_TEST_MODULE "test_expect"
+#ifdef UNITTEST_FRAMEWORK_LIBRARY_EXIST
+#include <boost/test/unit_test.hpp>
+#else
+#define BOOST_TEST_NO_LIB
+#include <boost/test/included/unit_test.hpp>
+#endif
+#include <toml.hpp>
+#include <map>
+#include <unordered_map>
+#include <list>
+#include <deque>
+#include <array>
+
+BOOST_AUTO_TEST_CASE(test_expect)
+{
+    {
+        toml::value v1(42);
+        toml::value v2(3.14);
+        const auto v1_or_0 = toml::expect<int>(v1).unwrap_or(0);
+        const auto v2_or_0 = toml::expect<int>(v2).unwrap_or(0);
+        BOOST_TEST(42 == v1_or_0);
+        BOOST_TEST( 0 == v2_or_0);
+
+        const auto v1_or_none = toml::expect<int>(v1).map([](int i){return std::to_string(i);}).unwrap_or(std::string("none"));
+        const auto v2_or_none = toml::expect<int>(v2).map([](int i){return std::to_string(i);}).unwrap_or(std::string("none"));
+        BOOST_TEST("42" ==   v1_or_none);
+        BOOST_TEST("none" == v2_or_none);
+    }
+}