temporary_materialisation.cpp

// Example showing when temporary materialisation and copy elision occurs.

struct S {
  S();
  ~S();
  S(const S&);
  S& operator=(const S&);
  S(S&&) noexcept;
  S& operator=(S&&) noexcept;

  S& set(int);
};

void h();

void f() {
    // initialisation causes temporary materialisation => copy elision
    auto s = S();
    h();
}

void g() {
    // calling set() causes temporary materialisation => copy not elided
    auto s = S().set(42);
    h();
}