add unary_visitor test

mapbox · Jun 24, 2014 · 3b31c34 · 3b31c34
1 parent 54d07c9
commit 3b31c34
Showing 1 changed file with 30 additions and 0 deletions.
diff --git a/test/unit.cpp b/test/unit.cpp
@@ -10,6 +10,25 @@
 
 using namespace mapbox;
 
+template <typename T>
+struct mutating_visitor : util::static_visitor<>
+{
+    mutating_visitor(T & val)
+        : val_(val) {}
+
+    void operator() (T & val) const
+    {
+        val = val_;
+    }
+
+    template <typename T1>
+    void operator() (T1& ) const {} // no-op
+
+    T & val_;
+};
+
+
+
 TEST_CASE( "variant version", "[variant]" ) {
     unsigned int version = VARIANT_VERSION;
     REQUIRE(version == 100);
@@ -208,6 +227,17 @@ TEST_CASE( "variant default constructor", "variant()" ) {
     REQUIRE((util::variant<int, double, std::string>().get_type_index() == 2));
 }
 
+
+TEST_CASE( "variant visitation", "unary visitor" )
+{
+    util::variant<int, double, std::string> var(123);
+    REQUIRE(var.get<int>() == 123);
+    int val = 456;
+    mutating_visitor<int> visitor(val);
+    util::apply_visitor(visitor,var);
+    REQUIRE(var.get<int>() == 456);
+}
+
 int main (int argc, char* const argv[])
 {
     int result = Catch::Session().run( argc, argv );