p2-0x.cpp revision 244ee7b89a483fd3764637abdf95de2893b437d0
11e7fc3d31e17fbe314f86de96aac6e9a2f297167Richard Smith// RUN: %clang_cc1 -fsyntax-only -std=c++11 -pedantic -verify -fcxx-exceptions %s -fconstexpr-depth 128 2c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith 3c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// A conditional-expression is a core constant expression unless it involves one 4c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// of the following as a potentially evaluated subexpression [...]: 5c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith 6c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// - this (5.1.1 [expr.prim.general]) [Note: when evaluating a constant 7c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// expression, function invocation substitution (7.1.5 [dcl.constexpr]) 8c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// replaces each occurrence of this in a constexpr member function with a 9c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// pointer to the class object. -end note]; 10c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smithstruct This { 11c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith int this1 : this1; // expected-error {{undeclared}} 12c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith int this2 : this->this1; // expected-error {{invalid}} 13c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith void this3() { 14c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith int n1[this->this1]; // expected-warning {{variable length array}} 15c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith int n2[this1]; // expected-warning {{variable length array}} 16c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith (void)n1, (void)n2; 17c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith } 18c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith}; 19c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith 20c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// - an invocation of a function other than a constexpr constructor for a 21c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// literal class or a constexpr function [ Note: Overload resolution (13.3) 22c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// is applied as usual - end note ]; 23c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smithstruct NonConstexpr1 { 24c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith static int f() { return 1; } // expected-note {{here}} 25c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith int n : f(); // expected-error {{constant expression}} expected-note {{non-constexpr function 'f' cannot be used in a constant expression}} 26c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith}; 27c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smithstruct NonConstexpr2 { 28c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith constexpr NonConstexpr2(); // expected-note {{here}} 29c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith int n; 30c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith}; 31c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smithstruct NonConstexpr3 { 32c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith NonConstexpr3(); 33c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith int m : NonConstexpr2().n; // expected-error {{constant expression}} expected-note {{undefined constructor 'NonConstexpr2'}} 34c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith}; 35c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smithstruct NonConstexpr4 { 3651201882382fb40c9456a06c7f93d6ddd4a57712Richard Smith NonConstexpr4(); // expected-note {{declared here}} 37c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith int n; 38c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith}; 39c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smithstruct NonConstexpr5 { 4051201882382fb40c9456a06c7f93d6ddd4a57712Richard Smith int n : NonConstexpr4().n; // expected-error {{constant expression}} expected-note {{non-constexpr constructor 'NonConstexpr4' cannot be used in a constant expression}} 41c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith}; 42c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith 43c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// - an invocation of an undefined constexpr function or an undefined 44c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// constexpr constructor; 45c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smithstruct UndefinedConstexpr { 46c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith constexpr UndefinedConstexpr(); 47c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith static constexpr int undefinedConstexpr1(); // expected-note {{here}} 48c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith int undefinedConstexpr2 : undefinedConstexpr1(); // expected-error {{constant expression}} expected-note {{undefined function 'undefinedConstexpr1' cannot be used in a constant expression}} 49c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith}; 50c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith 51c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// - an invocation of a constexpr function with arguments that, when substituted 52c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// by function invocation substitution (7.1.5), do not produce a constant 53c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// expression; 54c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smithnamespace NonConstExprReturn { 55c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith static constexpr const int &id_ref(const int &n) { 56c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith return n; // expected-note {{reference to temporary cannot be returned from a constexpr function}} 57c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith } 58c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith struct NonConstExprFunction { 5908d6e032a2a0a8656d12b3b7b93942987bb12eb7Richard Smith int n : id_ref( // expected-error {{constant expression}} expected-note {{in call to 'id_ref(16)'}} 60c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith 16 // expected-note {{temporary created here}} 61c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith ); 62c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith }; 63c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith constexpr const int *address_of(const int &a) { 64c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith return &a; // expected-note {{pointer to 'n' cannot be returned from a constexpr function}} 65c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith } 66c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith constexpr const int *return_param(int n) { // expected-note {{declared here}} 6708d6e032a2a0a8656d12b3b7b93942987bb12eb7Richard Smith return address_of(n); // expected-note {{in call to 'address_of(n)'}} 68c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith } 69c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith struct S { 7008d6e032a2a0a8656d12b3b7b93942987bb12eb7Richard Smith int n : *return_param(0); // expected-error {{constant expression}} expected-note {{in call to 'return_param(0)'}} 71c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith }; 72c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith} 73c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith 74c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// - an invocation of a constexpr constructor with arguments that, when 75c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// substituted by function invocation substitution (7.1.5), do not produce all 76c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// constant expressions for the constructor calls and full-expressions in the 77c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// mem-initializers (including conversions); 78c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smithnamespace NonConstExprCtor { 79c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith struct T { 80c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith constexpr T(const int &r) : 81099e7f647ccda915513f2b2ec53352dc756082d3Richard Smith r(r) { // expected-note 2{{reference to temporary cannot be used to initialize a member in a constant expression}} 82c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith } 83c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith const int &r; 84c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith }; 85c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith constexpr int n = 0; 86c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith constexpr T t1(n); // ok 87099e7f647ccda915513f2b2ec53352dc756082d3Richard Smith constexpr T t2(0); // expected-error {{must be initialized by a constant expression}} expected-note {{temporary created here}} expected-note {{in call to 'T(0)'}} 88c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith 89c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith struct S { 9008d6e032a2a0a8656d12b3b7b93942987bb12eb7Richard Smith int n : T(4).r; // expected-error {{constant expression}} expected-note {{temporary created here}} expected-note {{in call to 'T(4)'}} 91c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith }; 92c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith} 93c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith 94c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// - an invocation of a constexpr function or a constexpr constructor that would 95c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// exceed the implementation-defined recursion limits (see Annex B); 96c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smithnamespace RecursionLimits { 97c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith constexpr int RecurseForever(int n) { 981e7fc3d31e17fbe314f86de96aac6e9a2f297167Richard Smith return n + RecurseForever(n+1); // expected-note {{constexpr evaluation exceeded maximum depth of 128 calls}} expected-note 9{{in call to 'RecurseForever(}} expected-note {{skipping 118 calls}} 99c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith } 100c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith struct AlsoRecurseForever { 101c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith constexpr AlsoRecurseForever(int n) : 1021e7fc3d31e17fbe314f86de96aac6e9a2f297167Richard Smith n(AlsoRecurseForever(n+1).n) // expected-note {{constexpr evaluation exceeded maximum depth of 128 calls}} expected-note 9{{in call to 'AlsoRecurseForever(}} expected-note {{skipping 118 calls}} 103c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith {} 104c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith int n; 105c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith }; 106c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith struct S { 10708d6e032a2a0a8656d12b3b7b93942987bb12eb7Richard Smith int k : RecurseForever(0); // expected-error {{constant expression}} expected-note {{in call to}} 10808d6e032a2a0a8656d12b3b7b93942987bb12eb7Richard Smith int l : AlsoRecurseForever(0).n; // expected-error {{constant expression}} expected-note {{in call to}} 109c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith }; 110c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith} 111c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith 112c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// FIXME: 113c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// - an operation that would have undefined behavior [Note: including, for 114c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// example, signed integer overflow (Clause 5 [expr]), certain pointer 115c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// arithmetic (5.7 [expr.add]), division by zero (5.6 [expr.mul]), or certain 116c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// shift operations (5.8 [expr.shift]) -end note]; 117c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smithnamespace UndefinedBehavior { 118c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith void f(int n) { 119c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith switch (n) { 120c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith case (int)4.4e9: // expected-error {{constant expression}} expected-note {{value 4.4E+9 is outside the range of representable values of type 'int'}} 121c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith case (int)(unsigned)(long long)4.4e9: // ok 122c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith case (float)1e300: // expected-error {{constant expression}} expected-note {{value 1.0E+300 is outside the range of representable values of type 'float'}} 123c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith case (int)((float)1e37 / 1e30): // ok 124c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith case (int)(__fp16)65536: // expected-error {{constant expression}} expected-note {{value 65536 is outside the range of representable values of type 'half'}} 125c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith break; 126c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith } 127c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith } 128c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith 129c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith struct S { 130c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith int m; 131c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith }; 132c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith constexpr S s = { 5 }; // expected-note {{declared here}} 133c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith constexpr const int *p = &s.m + 1; 134c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith constexpr const int &f(const int *q) { 135c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith return q[0]; // expected-note {{dereferenced pointer past the end of subobject of 's' is not a constant expression}} 136c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith } 13761e616206413d1779c7545c7a8ad1ce1129ad9c1Richard Smith constexpr int n = (f(p), 0); // expected-error {{constant expression}} expected-note {{in call to 'f(&s.m + 1)'}} 138c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith struct T { 139244ee7b89a483fd3764637abdf95de2893b437d0Richard Smith int n : f(p); // expected-error {{not an integral constant expression}} expected-note {{read of dereferenced one-past-the-end pointer}} 140c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith }; 141b4e85ed51905fc94378d7b4ff62b06e0d08042b7Richard Smith 142b4e85ed51905fc94378d7b4ff62b06e0d08042b7Richard Smith namespace Ptr { 143b4e85ed51905fc94378d7b4ff62b06e0d08042b7Richard Smith struct A {}; 144b4e85ed51905fc94378d7b4ff62b06e0d08042b7Richard Smith struct B : A { int n; }; 145b4e85ed51905fc94378d7b4ff62b06e0d08042b7Richard Smith B a[3][3]; 146b4e85ed51905fc94378d7b4ff62b06e0d08042b7Richard Smith constexpr B *p = a[0] + 4; // expected-error {{constant expression}} expected-note {{element 4 of array of 3 elements}} 147b4e85ed51905fc94378d7b4ff62b06e0d08042b7Richard Smith B b = {}; 148b4e85ed51905fc94378d7b4ff62b06e0d08042b7Richard Smith constexpr A *pa = &b + 1; // expected-error {{constant expression}} expected-note {{base class of pointer past the end}} 149b4e85ed51905fc94378d7b4ff62b06e0d08042b7Richard Smith constexpr B *pb = (B*)((A*)&b + 1); // expected-error {{constant expression}} expected-note {{derived class of pointer past the end}} 150b4e85ed51905fc94378d7b4ff62b06e0d08042b7Richard Smith constexpr const int *pn = &(&b + 1)->n; // expected-error {{constant expression}} expected-note {{field of pointer past the end}} 151b4e85ed51905fc94378d7b4ff62b06e0d08042b7Richard Smith constexpr B *parr = &a[3][0]; // expected-error {{constant expression}} expected-note {{array element of pointer past the end}} 152b4e85ed51905fc94378d7b4ff62b06e0d08042b7Richard Smith 153b4e85ed51905fc94378d7b4ff62b06e0d08042b7Richard Smith constexpr A *na = nullptr; 154b4e85ed51905fc94378d7b4ff62b06e0d08042b7Richard Smith constexpr B *nb = nullptr; 155b4e85ed51905fc94378d7b4ff62b06e0d08042b7Richard Smith constexpr A &ra = *nb; // expected-error {{constant expression}} expected-note {{cannot access base class of null pointer}} 156b4e85ed51905fc94378d7b4ff62b06e0d08042b7Richard Smith constexpr B &rb = (B&)*na; // expected-error {{constant expression}} expected-note {{cannot access derived class of null pointer}} 157b4e85ed51905fc94378d7b4ff62b06e0d08042b7Richard Smith static_assert((A*)nb == 0, ""); 158b4e85ed51905fc94378d7b4ff62b06e0d08042b7Richard Smith static_assert((B*)na == 0, ""); 159b4e85ed51905fc94378d7b4ff62b06e0d08042b7Richard Smith constexpr const int &nf = nb->n; // expected-error {{constant expression}} expected-note {{cannot access field of null pointer}} 160b4e85ed51905fc94378d7b4ff62b06e0d08042b7Richard Smith constexpr const int &np = (*(int(*)[4])nullptr)[2]; // expected-error {{constant expression}} expected-note {{cannot access array element of null pointer}} 161b4e85ed51905fc94378d7b4ff62b06e0d08042b7Richard Smith } 162c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith} 163c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith 164c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// - a lambda-expression (5.1.2); 165c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smithstruct Lambda { 166c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith // FIXME: clang crashes when trying to parse this! Revisit this check once 167c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith // lambdas are fully implemented. 168c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith //int n : []{ return 1; }(); 169c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith}; 170c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith 171c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// - an lvalue-to-rvalue conversion (4.1) unless it is applied to 1727098cbd601ad915aed22d4b5850da99359f25bf3Richard Smithnamespace LValueToRValue { 1737098cbd601ad915aed22d4b5850da99359f25bf3Richard Smith // - a non-volatile glvalue of integral or enumeration type that refers to a 1747098cbd601ad915aed22d4b5850da99359f25bf3Richard Smith // non-volatile const object with a preceding initialization, initialized 1757098cbd601ad915aed22d4b5850da99359f25bf3Richard Smith // with a constant expression [Note: a string literal (2.14.5 [lex.string]) 1767098cbd601ad915aed22d4b5850da99359f25bf3Richard Smith // corresponds to an array of such objects. -end note], or 1777098cbd601ad915aed22d4b5850da99359f25bf3Richard Smith volatile const int vi = 1; // expected-note {{here}} 1787098cbd601ad915aed22d4b5850da99359f25bf3Richard Smith const int ci = 1; 1797098cbd601ad915aed22d4b5850da99359f25bf3Richard Smith volatile const int &vrci = ci; 1807098cbd601ad915aed22d4b5850da99359f25bf3Richard Smith static_assert(vi, ""); // expected-error {{constant expression}} expected-note {{read of volatile-qualified type 'const volatile int'}} 1817098cbd601ad915aed22d4b5850da99359f25bf3Richard Smith static_assert(const_cast<int&>(vi), ""); // expected-error {{constant expression}} expected-note {{read of volatile object 'vi'}} 1827098cbd601ad915aed22d4b5850da99359f25bf3Richard Smith static_assert(vrci, ""); // expected-error {{constant expression}} expected-note {{read of volatile-qualified type}} 1837098cbd601ad915aed22d4b5850da99359f25bf3Richard Smith 1847098cbd601ad915aed22d4b5850da99359f25bf3Richard Smith // - a non-volatile glvalue of literal type that refers to a non-volatile 1857098cbd601ad915aed22d4b5850da99359f25bf3Richard Smith // object defined with constexpr, or that refers to a sub-object of such an 1867098cbd601ad915aed22d4b5850da99359f25bf3Richard Smith // object, or 1877098cbd601ad915aed22d4b5850da99359f25bf3Richard Smith struct S { 1887098cbd601ad915aed22d4b5850da99359f25bf3Richard Smith constexpr S(int=0) : i(1), v(1) {} 1897098cbd601ad915aed22d4b5850da99359f25bf3Richard Smith constexpr S(const S &s) : i(2), v(2) {} 1907098cbd601ad915aed22d4b5850da99359f25bf3Richard Smith int i; 1917098cbd601ad915aed22d4b5850da99359f25bf3Richard Smith volatile int v; 1927098cbd601ad915aed22d4b5850da99359f25bf3Richard Smith }; 1937098cbd601ad915aed22d4b5850da99359f25bf3Richard Smith constexpr S s; 1947098cbd601ad915aed22d4b5850da99359f25bf3Richard Smith constexpr volatile S vs; // expected-note {{here}} 1957098cbd601ad915aed22d4b5850da99359f25bf3Richard Smith constexpr const volatile S &vrs = s; 1967098cbd601ad915aed22d4b5850da99359f25bf3Richard Smith static_assert(s.i, ""); 1977098cbd601ad915aed22d4b5850da99359f25bf3Richard Smith static_assert(s.v, ""); // expected-error {{constant expression}} expected-note {{read of volatile-qualified type}} 1987098cbd601ad915aed22d4b5850da99359f25bf3Richard Smith static_assert(vs.i, ""); // expected-error {{constant expression}} expected-note {{read of volatile-qualified type}} 1997098cbd601ad915aed22d4b5850da99359f25bf3Richard Smith static_assert(const_cast<int&>(vs.i), ""); // expected-error {{constant expression}} expected-note {{read of volatile object 'vs'}} 2007098cbd601ad915aed22d4b5850da99359f25bf3Richard Smith static_assert(vrs.i, ""); // expected-error {{constant expression}} expected-note {{read of volatile-qualified type}} 2017098cbd601ad915aed22d4b5850da99359f25bf3Richard Smith 2027098cbd601ad915aed22d4b5850da99359f25bf3Richard Smith // - a non-volatile glvalue of literal type that refers to a non-volatile 2037098cbd601ad915aed22d4b5850da99359f25bf3Richard Smith // temporary object whose lifetime has not ended, initialized with a 2047098cbd601ad915aed22d4b5850da99359f25bf3Richard Smith // constant expression; 2057098cbd601ad915aed22d4b5850da99359f25bf3Richard Smith constexpr volatile S f() { return S(); } 2067098cbd601ad915aed22d4b5850da99359f25bf3Richard Smith static_assert(f().i, ""); // ok! there's no lvalue-to-rvalue conversion here! 2077098cbd601ad915aed22d4b5850da99359f25bf3Richard Smith static_assert(((volatile const S&&)(S)0).i, ""); // expected-error {{constant expression}} expected-note {{subexpression}} 2087098cbd601ad915aed22d4b5850da99359f25bf3Richard Smith} 209c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith 210c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// FIXME: 211c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// 2127098cbd601ad915aed22d4b5850da99359f25bf3Richard Smith// DR1312: The proposed wording for this defect has issues, so we ignore this 2137098cbd601ad915aed22d4b5850da99359f25bf3Richard Smith// bullet and instead prohibit casts from pointers to cv void (see core-20842 2147098cbd601ad915aed22d4b5850da99359f25bf3Richard Smith// and core-20845). 215c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// 216c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// - an lvalue-to-rvalue conversion (4.1 [conv.lval]) that is applied to a 217c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// glvalue of type cv1 T that refers to an object of type cv2 U, where T and U 218c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// are neither the same type nor similar types (4.4 [conv.qual]); 219c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith 220c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// FIXME: 221c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// - an lvalue-to-rvalue conversion (4.1) that is applied to a glvalue that 222c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// refers to a non-active member of a union or a subobject thereof; 223c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith 224c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// - an id-expression that refers to a variable or data member of reference type 225c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// unless the reference has a preceding initialization, initialized with a 226c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// constant expression; 227c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smithnamespace References { 228c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith const int a = 2; 229c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith int &b = *const_cast<int*>(&a); 2307098cbd601ad915aed22d4b5850da99359f25bf3Richard Smith int c = 10; // expected-note 2 {{here}} 231c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith int &d = c; 232c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith constexpr int e = 42; 233c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith int &f = const_cast<int&>(e); 234c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith extern int &g; 235099e7f647ccda915513f2b2ec53352dc756082d3Richard Smith constexpr int &h(); // expected-note 2{{here}} 236099e7f647ccda915513f2b2ec53352dc756082d3Richard Smith int &i = h(); // expected-note {{here}} expected-note {{undefined function 'h' cannot be used in a constant expression}} 237c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith constexpr int &j() { return b; } 238c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith int &k = j(); 239c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith 240c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith struct S { 241c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith int A : a; 242c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith int B : b; 2437098cbd601ad915aed22d4b5850da99359f25bf3Richard Smith int C : c; // expected-error {{constant expression}} expected-note {{read of non-const variable 'c'}} 2447098cbd601ad915aed22d4b5850da99359f25bf3Richard Smith int D : d; // expected-error {{constant expression}} expected-note {{read of non-const variable 'c'}} 245c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith int D2 : &d - &c + 1; 246c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith int E : e / 2; 247c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith int F : f - 11; 248c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith int G : g; // expected-error {{constant expression}} 249c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith int H : h(); // expected-error {{constant expression}} expected-note {{undefined function 'h'}} 250099e7f647ccda915513f2b2ec53352dc756082d3Richard Smith int I : i; // expected-error {{constant expression}} expected-note {{initializer of 'i' is not a constant expression}} 251c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith int J : j(); 252c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith int K : k; 253c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith }; 254c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith} 255c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith 256c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// - a dynamic_cast (5.2.7); 257c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smithnamespace DynamicCast { 258c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith struct S { int n; }; 259c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith constexpr S s { 16 }; 260c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith struct T { 261c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith int n : dynamic_cast<const S*>(&s)->n; // expected-warning {{constant expression}} expected-note {{dynamic_cast}} 262c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith }; 263c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith} 264c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith 265c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// - a reinterpret_cast (5.2.10); 266c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smithnamespace ReinterpretCast { 267c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith struct S { int n; }; 268c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith constexpr S s { 16 }; 269c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith struct T { 270c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith int n : reinterpret_cast<const S*>(&s)->n; // expected-warning {{constant expression}} expected-note {{reinterpret_cast}} 271c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith }; 272c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith struct U { 273c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith int m : (long)(S*)6; // expected-warning {{constant expression}} expected-note {{reinterpret_cast}} 274c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith }; 275c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith} 276c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith 277c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// - a pseudo-destructor call (5.2.4); 278c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smithnamespace PseudoDtor { 279c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith int k; 280c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith typedef int I; 281c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith struct T { 282c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith int n : (k.~I(), 0); // expected-error {{constant expression}} expected-note{{subexpression}} 283c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith }; 284c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith} 285c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith 286c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// - increment or decrement operations (5.2.6, 5.3.2); 287c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smithnamespace IncDec { 288c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith int k = 2; 289c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith struct T { 290c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith int n : ++k; // expected-error {{constant expression}} 291c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith int m : --k; // expected-error {{constant expression}} 292c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith }; 293c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith} 294c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith 295c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// - a typeid expression (5.2.8) whose operand is of a polymorphic class type; 296c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smithnamespace std { 297c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith struct type_info { 298c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith virtual ~type_info(); 299c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith const char *name; 300c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith }; 301c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith} 302c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smithnamespace TypeId { 303c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith struct S { virtual void f(); }; 304c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith constexpr S *p = 0; 30547d2145675099893d702be4bc06bd9f26d8ddd13Richard Smith constexpr const std::type_info &ti1 = typeid(*p); // expected-error {{must be initialized by a constant expression}} expected-note {{typeid applied to expression of polymorphic type 'TypeId::S'}} 306c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith 307c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith struct T {} t; 30847d2145675099893d702be4bc06bd9f26d8ddd13Richard Smith constexpr const std::type_info &ti2 = typeid(t); 309c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith} 310c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith 311c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// - a new-expression (5.3.4); 312c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// - a delete-expression (5.3.5); 313c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smithnamespace NewDelete { 314c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith int *p = 0; 315c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith struct T { 316c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith int n : *new int(4); // expected-error {{constant expression}} expected-note {{subexpression}} 317c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith int m : (delete p, 2); // expected-error {{constant expression}} expected-note {{subexpression}} 318c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith }; 319c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith} 320c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith 321c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// - a relational (5.9) or equality (5.10) operator where the result is 322c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// unspecified; 323c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smithnamespace UnspecifiedRelations { 324c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith int a, b; 325c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith constexpr int *p = &a, *q = &b; 326c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith // C++11 [expr.rel]p2: If two pointers p and q of the same type point to 327c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith // different objects that are not members of the same array or to different 328c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith // functions, or if only one of them is null, the results of p<q, p>q, p<=q, 329c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith // and p>=q are unspecified. 330c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith constexpr bool u1 = p < q; // expected-error {{constant expression}} 331c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith constexpr bool u2 = p > q; // expected-error {{constant expression}} 332c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith constexpr bool u3 = p <= q; // expected-error {{constant expression}} 333c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith constexpr bool u4 = p >= q; // expected-error {{constant expression}} 334c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith constexpr bool u5 = p < 0; // expected-error {{constant expression}} 335c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith constexpr bool u6 = p <= 0; // expected-error {{constant expression}} 336c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith constexpr bool u7 = p > 0; // expected-error {{constant expression}} 337c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith constexpr bool u8 = p >= 0; // expected-error {{constant expression}} 338c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith constexpr bool u9 = 0 < q; // expected-error {{constant expression}} 339c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith constexpr bool u10 = 0 <= q; // expected-error {{constant expression}} 340c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith constexpr bool u11 = 0 > q; // expected-error {{constant expression}} 341c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith constexpr bool u12 = 0 >= q; // expected-error {{constant expression}} 342c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith void f(), g(); 343c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith 344c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith constexpr void (*pf)() = &f, (*pg)() = &g; 345c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith constexpr bool u13 = pf < pg; // expected-error {{constant expression}} 346c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith constexpr bool u14 = pf == pg; 347c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith 348c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith // FIXME: 349c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith // If two pointers point to non-static data members of the same object with 350c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith // different access control, the result is unspecified. 351c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith 352c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith // FIXME: 353c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith // [expr.rel]p3: Pointers to void can be compared [...] if both pointers 354c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith // represent the same address or are both the null pointer [...]; otherwise 355c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith // the result is unspecified. 356c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith 357c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith // FIXME: Implement comparisons of pointers to members. 358c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith // [expr.eq]p2: If either is a pointer to a virtual member function and 359c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith // neither is null, the result is unspecified. 360c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith} 361c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith 362c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// - an assignment or a compound assignment (5.17); or 363c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smithnamespace Assignment { 364c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith int k; 365c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith struct T { 366c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith int n : (k = 9); // expected-error {{constant expression}} 367c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith int m : (k *= 2); // expected-error {{constant expression}} 368c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith }; 369c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith 370c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith struct Literal { 371c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith constexpr Literal(const char *name) : name(name) {} 372c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith const char *name; 373c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith }; 374c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith struct Expr { 375c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith constexpr Expr(Literal l) : IsLiteral(true), l(l) {} 376c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith bool IsLiteral; 377c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith union { 378c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith Literal l; 379c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith // ... 380c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith }; 381c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith }; 382c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith struct MulEq { 383c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith constexpr MulEq(Expr a, Expr b) : LHS(a), RHS(b) {} 384c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith Expr LHS; 385c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith Expr RHS; 386c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith }; 387c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith constexpr MulEq operator*=(Expr a, Expr b) { return MulEq(a, b); } 388c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith Literal a("a"); 389c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith Literal b("b"); 390c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith MulEq c = a *= b; // ok 391c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith} 392c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith 393c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith// - a throw-expression (15.1) 394c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smithnamespace Throw { 395c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith struct S { 396c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith int n : (throw "hello", 10); // expected-error {{constant expression}} expected-note {{subexpression}} 397c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith }; 398c1c5f27c64dfc3332d53ad30e44d626e4f9afac3Richard Smith} 39963fe6814f339df30b8463b39995947cbdf920e48Douglas Gregor 40063fe6814f339df30b8463b39995947cbdf920e48Douglas Gregor// PR9999 40163fe6814f339df30b8463b39995947cbdf920e48Douglas Gregortemplate<bool v> 40263fe6814f339df30b8463b39995947cbdf920e48Douglas Gregorclass bitWidthHolding { 40363fe6814f339df30b8463b39995947cbdf920e48Douglas Gregorpublic: 40463fe6814f339df30b8463b39995947cbdf920e48Douglas Gregor static const 40563fe6814f339df30b8463b39995947cbdf920e48Douglas Gregor unsigned int width = (v == 0 ? 0 : bitWidthHolding<(v >> 1)>::width + 1); 40663fe6814f339df30b8463b39995947cbdf920e48Douglas Gregor}; 40763fe6814f339df30b8463b39995947cbdf920e48Douglas Gregor 40863fe6814f339df30b8463b39995947cbdf920e48Douglas Gregorstatic const int width=bitWidthHolding<255>::width; 40963fe6814f339df30b8463b39995947cbdf920e48Douglas Gregor 41063fe6814f339df30b8463b39995947cbdf920e48Douglas Gregortemplate<bool b> 41163fe6814f339df30b8463b39995947cbdf920e48Douglas Gregorstruct always_false { 41263fe6814f339df30b8463b39995947cbdf920e48Douglas Gregor static const bool value = false; 41363fe6814f339df30b8463b39995947cbdf920e48Douglas Gregor}; 41463fe6814f339df30b8463b39995947cbdf920e48Douglas Gregor 41563fe6814f339df30b8463b39995947cbdf920e48Douglas Gregortemplate<bool b> 41663fe6814f339df30b8463b39995947cbdf920e48Douglas Gregorstruct and_or { 41763fe6814f339df30b8463b39995947cbdf920e48Douglas Gregor static const bool and_value = b && and_or<always_false<b>::value>::and_value; 41863fe6814f339df30b8463b39995947cbdf920e48Douglas Gregor static const bool or_value = !b || and_or<always_false<b>::value>::or_value; 41963fe6814f339df30b8463b39995947cbdf920e48Douglas Gregor}; 42063fe6814f339df30b8463b39995947cbdf920e48Douglas Gregor 42163fe6814f339df30b8463b39995947cbdf920e48Douglas Gregorstatic const bool and_value = and_or<true>::and_value; 42263fe6814f339df30b8463b39995947cbdf920e48Douglas Gregorstatic const bool or_value = and_or<true>::or_value; 423