Apply-related code

apply/Makefile

@@ -0,0 +1,5 @@
+# Only define if needed:
+# TARGET = main.elf
+# SRCS = main.cc
+
+include ../config.mk

apply/main.cc

@@ -0,0 +1,30 @@
+#include <algorithm>
+#include <vector>
+
+// This code will kill your mood, steal your cat and invade russia
+
+template <typename F>
+auto apply(const F &f) -> decltype(f()) {
+    return f();
+}
+
+class Foo {
+    int val;
+
+  public:
+    Foo() = default;
+
+    Foo(const int &x)
+        : val(x) {}
+
+    Foo operator()() const { return Foo(2 * val); }
+
+    operator int() const { return val; }
+};
+
+int main() {
+    std::vector<Foo> v = {1, 2, 3, 4, 5};
+    std::vector<Foo> b;
+
+    std::transform(v.begin(), v.end(), std::back_inserter(b), apply<Foo>);
+}