Adding optional test

tests/CMakeLists.txt

@@ -10,6 +10,7 @@ set(CLI_TESTS
     SubcommandTest
     HelpTest
     NewParseTest
+    OptionalTest
     )
 
 set(CLI_MULTIONLY_TESTS

tests/OptionalTest.cpp

@@ -0,0 +1,48 @@
+#include <cstdlib>
+#include <iostream>
+
+#ifdef __has_include
+#if __has_include(<optional>)
+#include <optional>
+#define have_optional 1
+using std::experimental::optional;
+#elif __has_include(<experimental/optional>)
+#include <experimental/optional>
+#define have_optional 1
+using std::optional;
+#else
+#define have_optional 0
+#endif
+#endif
+
+#if have_optional
+
+template <typename T> std::istream &operator>>(std::istream &in, optional<T> &val) {
+    T v;
+    in >> v;
+    val = v;
+    return in;
+}
+
+#include "app_helper.hpp"
+
+TEST_F(TApp, OptionalTest) {
+    optional<int> opt;
+    app.add_option("-c,--count", opt);
+    run();
+    EXPECT_FALSE(opt);
+
+    app.reset();
+    args = {"-c", "1"};
+    run();
+    EXPECT_TRUE(opt);
+    EXPECT_EQ(*opt, 1);
+
+    app.reset();
+    args = {"--count", "3"};
+    run();
+    EXPECT_TRUE(opt);
+    EXPECT_EQ(*opt, 3);
+}
+
+#endif