src.cpp

struct foo {
  template <typename T>
  foo(T p_object) {
    p_object.process("hello");
  }
};

struct bar {
  void process(const std::string& p_value) { std::cout << p_value << "\n"; }
};

struct baz {};

foo f{bar{}};
foo b{baz{}}; // Fails at compile time.