1 files changed, 56 insertions, 0 deletions
diff --git a/lib/function_traits.cpp b/lib/function_traits.cpp
new file mode 100644
index 00000000..e3d27122
--- /dev/null
+++ b/lib/function_traits.cpp
@@ -0,0 +1,56 @@
+// SPDX-FileCopyrightText: 2018 Kitsune Ral <kitsune-ral@users.sf.net>
+// SPDX-License-Identifier: LGPL-2.1-or-later
+
+#include "function_traits.h"
+
+// Tests for function_traits<>
+
+using namespace Quotient;
+
+template <typename FnT>
+using fn_return_t = typename function_traits<FnT>::return_type;
+
+int f_();
+static_assert(std::is_same_v<fn_return_t<decltype(f_)>, int>,
+              "Test fn_return_t<>");
+
+void f1_(int, float);
+static_assert(std::is_same_v<fn_arg_t<decltype(f1_), 1>, float>,
+              "Test fn_arg_t<>");
+
+struct Fo {
+    int operator()();
+    static constexpr auto l = [] { return 0.0f; };
+    bool memFn();
+    void constMemFn() const&;
+    double field;
+    const double field2;
+};
+static_assert(std::is_same_v<fn_return_t<Fo>, int>,
+              "Test return type of function object");
+static_assert(std::is_same_v<fn_return_t<decltype(Fo::l)>, float>,
+              "Test return type of lambda");
+static_assert(std::is_same_v<fn_arg_t<decltype(&Fo::memFn)>, Fo>,
+              "Test first argument type of member function");
+static_assert(std::is_same_v<fn_return_t<decltype(&Fo::memFn)>, bool>,
+              "Test return type of member function");
+static_assert(std::is_same_v<fn_arg_t<decltype(&Fo::constMemFn)>, const Fo&>,
+              "Test first argument type of const member function");
+static_assert(std::is_void_v<fn_return_t<decltype(&Fo::constMemFn)>>,
+              "Test return type of const member function");
+static_assert(std::is_same_v<fn_return_t<decltype(&Fo::field)>, double&>,
+              "Test return type of a class member");
+static_assert(std::is_same_v<fn_return_t<decltype(&Fo::field2)>, const double&>,
+              "Test return type of a const class member");
+
+struct Fo1 {
+    void operator()(int);
+};
+static_assert(std::is_same_v<fn_arg_t<Fo1>, int>,
+              "Test fn_arg_t defaulting to first argument");
+
+template <typename T>
+[[maybe_unused]] static void ft(const std::vector<T>&);
+static_assert(
+    std::is_same<fn_arg_t<decltype(ft<double>)>, const std::vector<double>&>(),
+    "Test function templates");