llvm-project/clang/test/SemaCXX/cxx0x-initializer-references.cpp

// RUN: %clang_cc1 -std=c++11 -fsyntax-only -verify %s

struct one { char c; };
struct two { char c[2]; };

namespace reference {
  struct A {
    int i1, i2;
  };

  void single_init() {
    const int &cri1a = {1};
    const int &cri1b{1};

    int i = 1;
    int &ri1a = {i};
    int &ri1b{i};

    int &ri2 = {1}; // expected-error {{cannot bind to an initializer list temporary}}

    A a{1, 2};
    A &ra1a = {a};
    A &ra1b{a};
  }

  void reference_to_aggregate() {
    const A &ra1{1, 2};
    A &ra2{1, 2}; // expected-error {{cannot bind to an initializer list temporary}}

    const int (&arrayRef)[] = {1, 2, 3};
    static_assert(sizeof(arrayRef) == 3 * sizeof(int), "bad array size");
  }

  struct B {
    int i1;
  };

  void call() {
    one f(const int&);
    f({1});

    one g(int&); // expected-note {{passing argument}}
    g({1}); // expected-error {{cannot bind to an initializer list temporary}}
    int i = 0;
    g({i});

    void h(const B&);
    h({1});

    void a(B&); // expected-note {{passing argument}}
    a({1}); // expected-error {{cannot bind to an initializer list temporary}}
    B b{1};
    a({b});
  }

  void overloading() {
    one f(const int&);
    two f(const B&);

    // First is identity conversion, second is user-defined conversion.
    static_assert(sizeof(f({1})) == sizeof(one), "bad overload resolution");

    one g(int&);
    two g(const B&);

    static_assert(sizeof(g({1})) == sizeof(two), "bad overload resolution");

    one h(const int&);
    two h(const A&);

    static_assert(sizeof(h({1, 2})) == sizeof(two), "bad overload resolution");
  }

  struct X {};

  void edge_cases() {
    int const &b({0}); // expected-error {{cannot initialize reference type 'const int &' with a parenthesized initializer list}}
    const int (&arr)[3] ({1, 2, 3}); // expected-error {{cannot initialize reference type 'const int (&)[3]' with a parenthesized initializer list}}
    const X &x({}); // expected-error {{cannot initialize reference type 'const reference::X &' with a parenthesized initializer list}}
  }

  template<typename T> void dependent_edge_cases() {
    T b({}); // expected-error-re 3{{cannot initialize reference type {{.*}} with a parenthesized init}}
    T({}); // expected-error-re 3{{cannot initialize reference type {{.*}} with a parenthesized init}}
  }
  template void dependent_edge_cases<X>(); // ok
  template void dependent_edge_cases<const int&>(); // expected-note {{instantiation of}}
  template void dependent_edge_cases<const int(&)[1]>(); // expected-note {{instantiation of}}
  template void dependent_edge_cases<const X&>(); // expected-note {{instantiation of}}
}

namespace PR12182 {
  void f(int const(&)[3]);

  void g() {
      f({1, 2});
  }
}

namespace PR12660 {
  const int &i { 1 };
  struct S { S(int); } const &s { 2 };
}

namespace b7891773 {
  typedef void (*ptr)();
  template <class T> void f();
  int g(const ptr &);
  int k = g({ f<int> });
}

namespace inner_init {
  struct A { int n; };
  struct B { A &&r; };
  B b1 { 0 }; // expected-error {{reference to type 'inner_init::A' could not bind to an rvalue of type 'int'}}
  B b2 { { 0 } };
  B b3 { { { 0 } } }; // expected-warning {{braces around scalar init}}

  struct C { C(int); };   // expected-note 2{{candidate constructor (the implicit}} \
                          // expected-note {{candidate constructor not viable: cannot convert initializer list argument to 'int'}}
  struct D { C &&r; };
  D d1 { 0 }; // ok, 0 implicitly converts to C
  D d2 { { 0 } }; // ok, { 0 } calls C(0)
  D d3 { { { 0 } } }; // ok, { { 0 } } calls C({ 0 }), expected-warning {{braces around scalar init}}
  D d4 { { { { 0 } } } }; // expected-error {{no matching constructor for initialization of 'inner_init::C &&'}}

  struct E { explicit E(int); }; // expected-note 2{{here}}
  struct F { E &&r; };
  F f1 { 0 }; // expected-error {{could not bind to an rvalue of type 'int'}}
  F f2 { { 0 } }; // expected-error {{chosen constructor is explicit}}
  F f3 { { { 0 } } }; // expected-error {{chosen constructor is explicit}}
}

namespace PR20844 {
  struct A {};
  struct B { operator A&(); } b;
  A &a{b}; // expected-error {{excess elements}} expected-note {{in initialization of temporary of type 'PR20844::A'}}
}

namespace PR21834 {
const int &a = (const int &){0}; // expected-error {{cannot bind to an initializer list}}
}