1// RUN: %clang_cc1 -triple %itanium_abi_triple -fsyntax-only -std=c++11 -verify %s 2 3// If an expression of literal class type is used in a context where an integral 4// constant expression is required, then that class type shall have a single 5// non-explicit conversion function to an integral or unscoped enumeration type 6namespace std_example { 7 8struct A { 9 constexpr A(int i) : val(i) { } 10 constexpr operator int() const { return val; } 11 constexpr operator long() const { return 43; } 12private: 13 int val; 14}; 15template<int> struct X { }; 16constexpr A a = 42; 17X<a> x; // ok, unique conversion to int 18int ary[a]; // expected-error {{size of array has non-integer type 'const std_example::A'}} 19 20} 21 22struct OK { 23 constexpr OK() {} 24 constexpr operator int() const { return 8; } 25} constexpr ok; 26extern struct Incomplete incomplete; // expected-note 4{{forward decl}} 27struct Explicit { 28 constexpr Explicit() {} 29 constexpr explicit operator int() const { return 4; } // expected-note 4{{here}} 30} constexpr expl; 31struct Ambiguous { 32 constexpr Ambiguous() {} 33 constexpr operator int() const { return 2; } // expected-note 4{{here}} 34 constexpr operator long() const { return 1; } // expected-note 4{{here}} 35} constexpr ambig; 36 37constexpr int test_ok = ok; // ok 38constexpr int test_explicit(expl); // ok 39constexpr int test_ambiguous = ambig; // ok 40 41static_assert(test_ok == 8, ""); 42static_assert(test_explicit == 4, ""); 43static_assert(test_ambiguous == 2, ""); 44 45// [expr.new]p6: Every constant-expression in a noptr-new-declarator shall be 46// an integral constant expression 47auto new1 = new int[1][ok]; 48auto new2 = new int[1][incomplete]; // expected-error {{incomplete}} 49auto new3 = new int[1][expl]; // expected-error {{explicit conversion}} 50auto new4 = new int[1][ambig]; // expected-error {{ambiguous conversion}} 51 52// [dcl.enum]p5: If the underlying type is not fixed [...] the initializing 53// value [...] shall be an integral constant expression. 54enum NotFixed { 55 enum1 = ok, 56 enum2 = incomplete, // expected-error {{incomplete}} 57 enum3 = expl, // expected-error {{explicit conversion}} 58 enum4 = ambig // expected-error {{ambiguous conversion}} 59}; 60 61// [dcl.align]p2: When the alignment-specifier is of the form 62// alignas(assignment-expression), the assignment-expression shall be an 63// integral constant expression 64alignas(ok) int alignas1; 65alignas(incomplete) int alignas2; // expected-error {{incomplete}} 66alignas(expl) int alignas3; // expected-error {{explicit conversion}} 67alignas(ambig) int alignas4; // expected-error {{ambiguous conversion}} 68 69// [dcl.array]p1: If the constant-expression is present, it shall be an integral 70// constant expression 71// FIXME: The VLA recovery results in us giving diagnostics which aren't great 72// here. 73int array1[ok]; 74int array2[incomplete]; // expected-error {{non-integer type}} 75int array3[expl]; // expected-error {{non-integer type}} 76int array4[ambig]; // expected-error {{non-integer type}} 77 78// [class.bit]p1: The constasnt-expression shall be an integral constant 79// expression 80struct Bitfields { 81 int bitfield1 : ok; 82 int bitfield2 : incomplete; // expected-error {{incomplete}} 83 int bitfield3 : expl; // expected-error {{explicit conversion}} 84 int bitfield4 : ambig; // expected-error {{ambiguous conversion}} 85}; 86