more push_back tests

test/push_front_function.cpp

@@ -0,0 +1,35 @@
+#include <tuple>
+#include <utility>
+#include <type_traits>
+#include <callable_traits/callable_traits.hpp>
+
+#ifndef CT_ASSERT
+#define CT_ASSERT(...) static_assert(__VA_ARGS__, #__VA_ARGS__)
+#endif //CT_ASSERT
+
+#ifdef CALLABLE_TRAITS_DISABLE_REFERENCE_QUALIFIERS
+#define RREF
+#else
+#define RREF &&
+#endif
+
+namespace ct = callable_traits;
+
+template<int I>
+struct N {};
+
+struct foo;
+
+template<typename... Ts>
+using sig = int(Ts...);
+
+int main() {
+
+    {
+        using f = sig<N<0>, N<1>, N<2>, N<3>, N<4>>;
+        using test = ct::push_front<f, int, char>;
+        using expect = sig<int, char, N<0>, N<1>, N<2>, N<3>, N<4>>;
+        CT_ASSERT(std::is_same<test, expect>::value);
+    }
+}
+