| 1 | // RUN: %clang_cc1 -fsyntax-only -std=c++03 -fdiagnostics-show-option -Wbind-to-temporary-copy -verify %s |
|---|
| 2 | |
|---|
| 3 | // C++03 requires that we check for a copy constructor when binding a |
|---|
| 4 | // reference to a temporary, since we are allowed to make a copy, Even |
|---|
| 5 | // though we don't actually make that copy, make sure that we diagnose |
|---|
| 6 | // cases where that copy constructor is somehow unavailable. As an |
|---|
| 7 | // extension, this is only a warning. |
|---|
| 8 | |
|---|
| 9 | struct X1 { |
|---|
| 10 | X1(); |
|---|
| 11 | explicit X1(const X1&); |
|---|
| 12 | }; |
|---|
| 13 | |
|---|
| 14 | struct X2 { |
|---|
| 15 | X2(); |
|---|
| 16 | |
|---|
| 17 | private: |
|---|
| 18 | X2(const X2&); // expected-note{{declared private here}} |
|---|
| 19 | }; |
|---|
| 20 | |
|---|
| 21 | struct X3 { |
|---|
| 22 | X3(); // expected-note{{requires 0 arguments, but 1 was provided}} |
|---|
| 23 | |
|---|
| 24 | private: |
|---|
| 25 | X3(X3&); // expected-note{{candidate constructor not viable: expects an l-value for 1st argument}} |
|---|
| 26 | }; |
|---|
| 27 | |
|---|
| 28 | // Check for instantiation of default arguments |
|---|
| 29 | template<typename T> |
|---|
| 30 | T get_value_badly() { |
|---|
| 31 | double *dp = 0; |
|---|
| 32 | // The extension doesn't extend far enough to turn this error into a warning. |
|---|
| 33 | T *tp = dp; // expected-error{{cannot initialize a variable of type 'int *' with an lvalue of type 'double *'}} |
|---|
| 34 | return T(); |
|---|
| 35 | } |
|---|
| 36 | |
|---|
| 37 | template<typename T> |
|---|
| 38 | struct X4 { |
|---|
| 39 | X4(); |
|---|
| 40 | X4(const X4&, T = get_value_badly<T>()); // expected-note{{in instantiation of}} |
|---|
| 41 | }; |
|---|
| 42 | |
|---|
| 43 | // Check for "dangerous" default arguments that could cause recursion. |
|---|
| 44 | struct X5 { |
|---|
| 45 | X5(); // expected-note {{requires 0 arguments}} |
|---|
| 46 | X5(const X5&, const X5& = X5()); // expected-warning{{no viable constructor copying parameter of type 'X5'}} expected-note {{requires 2 arguments}} |
|---|
| 47 | }; |
|---|
| 48 | |
|---|
| 49 | void g1(const X1&); |
|---|
| 50 | void g2(const X2&); |
|---|
| 51 | void g3(const X3&); |
|---|
| 52 | void g4(const X4<int>&); |
|---|
| 53 | void g5(const X5&); |
|---|
| 54 | |
|---|
| 55 | void test() { |
|---|
| 56 | g1(X1()); |
|---|
| 57 | g2(X2()); // expected-warning{{C++98 requires an accessible copy constructor for class 'X2' when binding a reference to a temporary; was private}} |
|---|
| 58 | g3(X3()); // expected-warning{{no viable constructor copying parameter of type 'X3'}} |
|---|
| 59 | g4(X4<int>()); |
|---|
| 60 | g5(X5()); // Generates a warning in the default argument. |
|---|
| 61 | } |
|---|
| 62 | |
|---|
| 63 | // Check that unavailable copy constructors still cause SFINAE failures. |
|---|
| 64 | template<int> struct int_c { }; |
|---|
| 65 | |
|---|
| 66 | template<typename T> T f(const T&); |
|---|
| 67 | |
|---|
| 68 | // Would be ambiguous with the next g(), except the instantiation failure in |
|---|
| 69 | // sizeof() prevents that. |
|---|
| 70 | template<typename T> |
|---|
| 71 | int &g(int_c<sizeof(f(T()))> * = 0); |
|---|
| 72 | |
|---|
| 73 | template<typename T> float &g(); |
|---|
| 74 | |
|---|
| 75 | void h() { |
|---|
| 76 | float &fp2 = g<X3>(); // Not ambiguous. |
|---|
| 77 | } |
|---|
| 78 | |
|---|