1 // RUN: %clang_cc1 -fsyntax-only -std=c++11 -pedantic -verify -fcxx-exceptions %s -fconstexpr-depth 128 -triple i686-pc-linux-gnu
3 // A conditional-expression is a core constant expression unless it involves one
4 // of the following as a potentially evaluated subexpression [...]:
6 // - this (5.1.1 [expr.prim.general]) [Note: when evaluating a constant
7 // expression, function invocation substitution (7.1.5 [dcl.constexpr])
8 // replaces each occurrence of this in a constexpr member function with a
9 // pointer to the class object. -end note];
11 int this1 : this1; // expected-error {{undeclared}}
12 int this2 : this->this1; // expected-error {{invalid}}
14 int n1[this->this1]; // expected-warning {{variable length array}}
15 int n2[this1]; // expected-warning {{variable length array}}
20 // - an invocation of a function other than a constexpr constructor for a
21 // literal class or a constexpr function [ Note: Overload resolution (13.3)
22 // is applied as usual - end note ];
23 struct NonConstexpr1 {
24 static int f() { return 1; } // expected-note {{here}}
25 int n : f(); // expected-error {{constant expression}} expected-note {{non-constexpr function 'f' cannot be used in a constant expression}}
27 struct NonConstexpr2 {
28 constexpr NonConstexpr2(); // expected-note {{here}}
31 struct NonConstexpr3 {
33 int m : NonConstexpr2().n; // expected-error {{constant expression}} expected-note {{undefined constructor 'NonConstexpr2'}}
35 struct NonConstexpr4 {
36 NonConstexpr4(); // expected-note {{declared here}}
39 struct NonConstexpr5 {
40 int n : NonConstexpr4().n; // expected-error {{constant expression}} expected-note {{non-constexpr constructor 'NonConstexpr4' cannot be used in a constant expression}}
43 // - an invocation of an undefined constexpr function or an undefined
44 // constexpr constructor;
45 struct UndefinedConstexpr {
46 constexpr UndefinedConstexpr();
47 static constexpr int undefinedConstexpr1(); // expected-note {{here}}
48 int undefinedConstexpr2 : undefinedConstexpr1(); // expected-error {{constant expression}} expected-note {{undefined function 'undefinedConstexpr1' cannot be used in a constant expression}}
51 // - an invocation of a constexpr function with arguments that, when substituted
52 // by function invocation substitution (7.1.5), do not produce a core constant
54 namespace NonConstExprReturn {
55 static constexpr const int &id_ref(const int &n) {
58 struct NonConstExprFunction {
59 int n : id_ref(16); // ok
61 constexpr const int *address_of(const int &a) {
64 constexpr const int *return_param(int n) { // expected-note {{declared here}}
68 int n : *return_param(0); // expected-error {{constant expression}} expected-note {{read of variable whose lifetime has ended}}
72 // - an invocation of a constexpr constructor with arguments that, when
73 // substituted by function invocation substitution (7.1.5), do not produce all
74 // constant expressions for the constructor calls and full-expressions in the
75 // mem-initializers (including conversions);
76 namespace NonConstExprCtor {
78 constexpr T(const int &r) :
84 constexpr T t1(n); // ok
85 constexpr T t2(0); // expected-error {{must be initialized by a constant expression}} expected-note {{temporary created here}} expected-note {{reference to temporary is not a constant expression}}
92 // - an invocation of a constexpr function or a constexpr constructor that would
93 // exceed the implementation-defined recursion limits (see Annex B);
94 namespace RecursionLimits {
95 constexpr int RecurseForever(int n) {
96 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}}
98 struct AlsoRecurseForever {
99 constexpr AlsoRecurseForever(int n) :
100 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}}
105 int k : RecurseForever(0); // expected-error {{constant expression}} expected-note {{in call to}}
106 int l : AlsoRecurseForever(0).n; // expected-error {{constant expression}} expected-note {{in call to}}
110 // DR1458: taking the address of an object of incomplete class type
111 namespace IncompleteClassTypeAddr {
114 constexpr S *p = &s; // ok
115 static_assert(p, "");
118 constexpr S (*p2)[] = &sArr; // ok
121 constexpr S *operator&() const { return nullptr; }
123 constexpr S *q = &s; // ok
124 static_assert(!q, "");
127 // - an operation that would have undefined behavior [Note: including, for
128 // example, signed integer overflow (Clause 5 [expr]), certain pointer
129 // arithmetic (5.7 [expr.add]), division by zero (5.6 [expr.mul]), or certain
130 // shift operations (5.8 [expr.shift]) -end note];
131 namespace UndefinedBehavior {
134 case (int)4.4e9: // expected-error {{constant expression}} expected-note {{value 4.4E+9 is outside the range of representable values of type 'int'}} expected-note {{previous case defined here}}
135 case (int)0x80000000u: // ok
136 case (int)10000000000ll: // expected-note {{here}}
137 case (unsigned int)10000000000ll: // expected-error {{duplicate case value}}
138 case (int)(unsigned)(long long)4.4e9: // ok
139 case (int)(float)1e300: // expected-error {{constant expression}} expected-note {{value 1.0E+300 is outside the range of representable values of type 'float'}} expected-error {{duplicate case value '2147483647'}} expected-note {{previous case defined here}}
140 case (int)((float)1e37 / 1e30): // ok
141 case (int)(__fp16)65536: // expected-error {{constant expression}} expected-note {{value 65536 is outside the range of representable values of type 'half'}} expected-error {{duplicate case value '2147483647'}}
146 constexpr int int_min = ~0x7fffffff;
147 constexpr int minus_int_min = -int_min; // expected-error {{constant expression}} expected-note {{value 2147483648 is outside the range}}
148 constexpr int div0 = 3 / 0; // expected-error {{constant expression}} expected-note {{division by zero}} expected-warning {{undefined}}
149 constexpr int mod0 = 3 % 0; // expected-error {{constant expression}} expected-note {{division by zero}} expected-warning {{undefined}}
150 constexpr int int_min_div_minus_1 = int_min / -1; // expected-error {{constant expression}} expected-note {{value 2147483648 is outside the range}}
151 constexpr int int_min_mod_minus_1 = int_min % -1; // expected-error {{constant expression}} expected-note {{value 2147483648 is outside the range}}
153 constexpr int shl_m1 = 0 << -1; // expected-error {{constant expression}} expected-note {{negative shift count -1}} expected-warning {{negative}}
154 constexpr int shl_0 = 0 << 0; // ok
155 constexpr int shl_31 = 0 << 31; // ok
156 constexpr int shl_32 = 0 << 32; // expected-error {{constant expression}} expected-note {{shift count 32 >= width of type 'int' (32}} expected-warning {{>= width of type}}
157 constexpr int shl_unsigned_negative = unsigned(-3) << 1; // ok
158 constexpr int shl_unsigned_into_sign = 1u << 31; // ok
159 constexpr int shl_unsigned_overflow = 1024u << 31; // ok
160 constexpr int shl_signed_negative = (-3) << 1; // expected-error {{constant expression}} expected-note {{left shift of negative value -3}}
161 constexpr int shl_signed_ok = 1 << 30; // ok
162 constexpr int shl_signed_into_sign = 1 << 31; // ok (DR1457)
163 constexpr int shl_signed_into_sign_2 = 0x7fffffff << 1; // ok (DR1457)
164 constexpr int shl_signed_off_end = 2 << 31; // expected-error {{constant expression}} expected-note {{signed left shift discards bits}} expected-warning {{signed shift result (0x100000000) requires 34 bits to represent, but 'int' only has 32 bits}}
165 constexpr int shl_signed_off_end_2 = 0x7fffffff << 2; // expected-error {{constant expression}} expected-note {{signed left shift discards bits}} expected-warning {{signed shift result (0x1FFFFFFFC) requires 34 bits to represent, but 'int' only has 32 bits}}
166 constexpr int shl_signed_overflow = 1024 << 31; // expected-error {{constant expression}} expected-note {{signed left shift discards bits}} expected-warning {{requires 43 bits to represent}}
167 constexpr int shl_signed_ok2 = 1024 << 20; // ok
169 constexpr int shr_m1 = 0 >> -1; // expected-error {{constant expression}} expected-note {{negative shift count -1}} expected-warning {{negative}}
170 constexpr int shr_0 = 0 >> 0; // ok
171 constexpr int shr_31 = 0 >> 31; // ok
172 constexpr int shr_32 = 0 >> 32; // expected-error {{constant expression}} expected-note {{shift count 32 >= width of type}} expected-warning {{>= width of type}}
177 constexpr S s = { 5 };
178 constexpr const int *p = &s.m + 1;
179 constexpr const int &f(const int *q) {
182 constexpr int n = (f(p), 0); // ok
184 int n : f(p); // expected-error {{not an integral constant expression}} expected-note {{read of dereferenced one-past-the-end pointer}}
189 struct B : A { int n; };
191 constexpr B *p = a[0] + 4; // expected-error {{constant expression}} expected-note {{element 4 of array of 3 elements}}
193 constexpr A *pa = &b + 1; // expected-error {{constant expression}} expected-note {{base class of pointer past the end}}
194 constexpr B *pb = (B*)((A*)&b + 1); // expected-error {{constant expression}} expected-note {{derived class of pointer past the end}}
195 constexpr const int *pn = &(&b + 1)->n; // expected-error {{constant expression}} expected-note {{field of pointer past the end}}
196 constexpr B *parr = &a[3][0]; // expected-error {{constant expression}} expected-note {{array element of pointer past the end}}
198 constexpr A *na = nullptr;
199 constexpr B *nb = nullptr;
200 constexpr A &ra = *nb; // expected-error {{constant expression}} expected-note {{cannot access base class of null pointer}}
201 constexpr B &rb = (B&)*na; // expected-error {{constant expression}} expected-note {{cannot access derived class of null pointer}}
202 static_assert((A*)nb == 0, "");
203 static_assert((B*)na == 0, "");
204 constexpr const int &nf = nb->n; // expected-error {{constant expression}} expected-note {{cannot access field of null pointer}}
205 constexpr const int &np = (*(int(*)[4])nullptr)[2]; // expected-error {{constant expression}} expected-note {{cannot access array element of null pointer}}
208 constexpr int f() const { return 0; }
210 constexpr int k1 = c.f(); // ok
211 constexpr int k2 = ((C*)nullptr)->f(); // expected-error {{constant expression}} expected-note {{cannot call member function on null pointer}}
212 constexpr int k3 = (&c)[1].f(); // expected-error {{constant expression}} expected-note {{cannot call member function on pointer past the end of object}}
214 constexpr int k4 = c2.f(); // ok!
216 constexpr int diff1 = &a[2] - &a[0];
217 constexpr int diff2 = &a[1][3] - &a[1][0];
218 constexpr int diff3 = &a[2][0] - &a[1][0]; // expected-error {{constant expression}} expected-note {{subtracted pointers are not elements of the same array}}
219 static_assert(&a[2][0] == &a[1][3], "");
220 constexpr int diff4 = (&b + 1) - &b;
221 constexpr int diff5 = &a[1][2].n - &a[1][0].n; // expected-error {{constant expression}} expected-note {{subtracted pointers are not elements of the same array}}
222 constexpr int diff6 = &a[1][2].n - &a[1][2].n;
223 constexpr int diff7 = (A*)&a[0][1] - (A*)&a[0][0]; // expected-error {{constant expression}} expected-note {{subtracted pointers are not elements of the same array}}
227 // Signed int overflow.
228 constexpr int n1 = 2 * 3 * 3 * 7 * 11 * 31 * 151 * 331; // ok
229 constexpr int n2 = 65536 * 32768; // expected-error {{constant expression}} expected-note {{value 2147483648 is outside the range of }}
230 constexpr int n3 = n1 + 1; // ok
231 constexpr int n4 = n3 + 1; // expected-error {{constant expression}} expected-note {{value 2147483648 is outside the range of }}
232 constexpr int n5 = -65536 * 32768; // ok
233 constexpr int n6 = 3 * -715827883; // expected-error {{constant expression}} expected-note {{value -2147483649 is outside the range of }}
234 constexpr int n7 = -n3 + -1; // ok
235 constexpr int n8 = -1 + n7; // expected-error {{constant expression}} expected-note {{value -2147483649 is outside the range of }}
236 constexpr int n9 = n3 - 0; // ok
237 constexpr int n10 = n3 - -1; // expected-error {{constant expression}} expected-note {{value 2147483648 is outside the range of }}
238 constexpr int n11 = -1 - n3; // ok
239 constexpr int n12 = -2 - n3; // expected-error {{constant expression}} expected-note {{value -2147483649 is outside the range of }}
240 constexpr int n13 = n5 + n5; // expected-error {{constant expression}} expected-note {{value -4294967296 is outside the range of }}
241 constexpr int n14 = n3 - n5; // expected-error {{constant expression}} expected-note {{value 4294967295 is outside the range of }}
242 constexpr int n15 = n5 * n5; // expected-error {{constant expression}} expected-note {{value 4611686018427387904 is outside the range of }}
243 constexpr signed char c1 = 100 * 2; // ok
244 constexpr signed char c2 = '\x64' * '\2'; // also ok
245 constexpr long long ll1 = 0x7fffffffffffffff; // ok
246 constexpr long long ll2 = ll1 + 1; // expected-error {{constant}} expected-note {{ 9223372036854775808 }}
247 constexpr long long ll3 = -ll1 - 1; // ok
248 constexpr long long ll4 = ll3 - 1; // expected-error {{constant}} expected-note {{ -9223372036854775809 }}
249 constexpr long long ll5 = ll3 * ll3; // expected-error {{constant}} expected-note {{ 85070591730234615865843651857942052864 }}
252 char melchizedek[2200000000];
253 typedef decltype(melchizedek[1] - melchizedek[0]) ptrdiff_t;
254 constexpr ptrdiff_t d1 = &melchizedek[0x7fffffff] - &melchizedek[0]; // ok
255 constexpr ptrdiff_t d2 = &melchizedek[0x80000000u] - &melchizedek[0]; // expected-error {{constant expression}} expected-note {{ 2147483648 }}
256 constexpr ptrdiff_t d3 = &melchizedek[0] - &melchizedek[0x80000000u]; // ok
257 constexpr ptrdiff_t d4 = &melchizedek[0] - &melchizedek[0x80000001u]; // expected-error {{constant expression}} expected-note {{ -2147483649 }}
259 // Unsigned int overflow.
260 static_assert(65536u * 65536u == 0u, ""); // ok
261 static_assert(4294967295u + 1u == 0u, ""); // ok
262 static_assert(0u - 1u == 4294967295u, ""); // ok
263 static_assert(~0u * ~0u == 1u, ""); // ok
265 // Floating-point overflow and NaN.
266 constexpr float f1 = 1e38f * 3.4028f; // ok
267 constexpr float f2 = 1e38f * 3.4029f; // expected-error {{constant expression}} expected-note {{floating point arithmetic produces an infinity}}
268 constexpr float f3 = 1e38f / -.2939f; // ok
269 constexpr float f4 = 1e38f / -.2938f; // expected-error {{constant expression}} expected-note {{floating point arithmetic produces an infinity}}
270 constexpr float f5 = 2e38f + 2e38f; // expected-error {{constant expression}} expected-note {{floating point arithmetic produces an infinity}}
271 constexpr float f6 = -2e38f - 2e38f; // expected-error {{constant expression}} expected-note {{floating point arithmetic produces an infinity}}
272 constexpr float f7 = 0.f / 0.f; // expected-error {{constant expression}} expected-note {{floating point arithmetic produces a NaN}}
276 // - a lambda-expression (5.1.2);
278 // FIXME: clang crashes when trying to parse this! Revisit this check once
279 // lambdas are fully implemented.
280 //int n : []{ return 1; }();
283 // - an lvalue-to-rvalue conversion (4.1) unless it is applied to
284 namespace LValueToRValue {
285 // - a non-volatile glvalue of integral or enumeration type that refers to a
286 // non-volatile const object with a preceding initialization, initialized
287 // with a constant expression [Note: a string literal (2.14.5 [lex.string])
288 // corresponds to an array of such objects. -end note], or
289 volatile const int vi = 1; // expected-note 2{{here}}
291 volatile const int &vrci = ci;
292 static_assert(vi, ""); // expected-error {{constant expression}} expected-note {{read of volatile-qualified type}}
293 static_assert(const_cast<int&>(vi), ""); // expected-error {{constant expression}} expected-note {{read of volatile object 'vi'}}
294 static_assert(vrci, ""); // expected-error {{constant expression}} expected-note {{read of volatile-qualified type}}
296 // - a non-volatile glvalue of literal type that refers to a non-volatile
297 // object defined with constexpr, or that refers to a sub-object of such an
300 constexpr V() : v(1) {}
301 volatile int v; // expected-note {{not literal because}}
303 constexpr V v; // expected-error {{non-literal type}}
305 constexpr S(int=0) : i(1), v(const_cast<volatile int&>(vi)) {}
306 constexpr S(const S &s) : i(2), v(const_cast<volatile int&>(vi)) {}
311 constexpr volatile S vs; // expected-note {{here}}
312 constexpr const volatile S &vrs = s; // ok
313 static_assert(s.i, "");
314 static_assert(s.v, ""); // expected-error {{constant expression}} expected-note {{read of volatile-qualified type}}
315 static_assert(const_cast<int&>(s.v), ""); // expected-error {{constant expression}} expected-note {{read of volatile object 'vi'}}
316 static_assert(vs.i, ""); // expected-error {{constant expression}} expected-note {{read of volatile-qualified type}}
317 static_assert(const_cast<int&>(vs.i), ""); // expected-error {{constant expression}} expected-note {{read of volatile object 'vs'}}
318 static_assert(vrs.i, ""); // expected-error {{constant expression}} expected-note {{read of volatile-qualified type}}
320 // - a non-volatile glvalue of literal type that refers to a non-volatile
321 // temporary object whose lifetime has not ended, initialized with a
322 // constant expression;
323 constexpr volatile S f() { return S(); }
324 static_assert(f().i, ""); // ok! there's no lvalue-to-rvalue conversion here!
325 static_assert(((volatile const S&&)(S)0).i, ""); // expected-error {{constant expression}}
328 // DR1312: The proposed wording for this defect has issues, so we ignore this
329 // bullet and instead prohibit casts from pointers to cv void (see core-20842
332 // - an lvalue-to-rvalue conversion (4.1 [conv.lval]) that is applied to a
333 // glvalue of type cv1 T that refers to an object of type cv2 U, where T and U
334 // are neither the same type nor similar types (4.4 [conv.qual]);
336 // - an lvalue-to-rvalue conversion (4.1) that is applied to a glvalue that
337 // refers to a non-active member of a union or a subobject thereof;
338 namespace LValueToRValueUnion {
339 // test/SemaCXX/constant-expression-cxx11.cpp contains more thorough testing
341 union U { int a, b; } constexpr u = U();
342 static_assert(u.a == 0, "");
343 constexpr const int *bp = &u.b;
344 constexpr int b = *bp; // expected-error {{constant expression}} expected-note {{read of member 'b' of union with active member 'a'}}
347 constexpr const int *pua = &pu.a;
348 constexpr const int *pub = &pu.b;
349 constexpr U pu = { .b = 1 }; // expected-warning {{C99 feature}}
350 constexpr const int a2 = *pua; // expected-error {{constant expression}} expected-note {{read of member 'a' of union with active member 'b'}}
351 constexpr const int b2 = *pub; // ok
354 // - an id-expression that refers to a variable or data member of reference type
355 // unless the reference has a preceding initialization, initialized with a
356 // constant expression;
357 namespace References {
359 int &b = *const_cast<int*>(&a);
360 int c = 10; // expected-note 2 {{here}}
362 constexpr int e = 42;
363 int &f = const_cast<int&>(e);
365 constexpr int &h(); // expected-note {{here}}
366 int &i = h(); // expected-note {{here}}
367 constexpr int &j() { return b; }
373 int C : c; // expected-error {{constant expression}} expected-note {{read of non-const variable 'c'}}
374 int D : d; // expected-error {{constant expression}} expected-note {{read of non-const variable 'c'}}
375 int D2 : &d - &c + 1;
378 int G : g; // expected-error {{constant expression}}
379 int H : h(); // expected-error {{constant expression}} expected-note {{undefined function 'h'}}
380 int I : i; // expected-error {{constant expression}} expected-note {{initializer of 'i' is not a constant expression}}
386 // - a dynamic_cast (5.2.7);
387 namespace DynamicCast {
389 constexpr S s { 16 };
391 int n : dynamic_cast<const S*>(&s)->n; // expected-warning {{constant expression}} expected-note {{dynamic_cast}}
395 // - a reinterpret_cast (5.2.10);
396 namespace ReinterpretCast {
398 constexpr S s { 16 };
400 int n : reinterpret_cast<const S*>(&s)->n; // expected-warning {{constant expression}} expected-note {{reinterpret_cast}}
403 int m : (long)(S*)6; // expected-warning {{constant expression}} expected-note {{reinterpret_cast}}
407 // - a pseudo-destructor call (5.2.4);
408 namespace PseudoDtor {
412 int n : (k.~I(), 0); // expected-error {{constant expression}}
416 // - increment or decrement operations (5.2.6, 5.3.2);
420 int n : ++k; // expected-error {{constant expression}}
421 int m : --k; // expected-error {{constant expression}}
425 // - a typeid expression (5.2.8) whose operand is of a polymorphic class type;
428 virtual ~type_info();
433 struct S { virtual void f(); };
435 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'}}
438 constexpr const std::type_info &ti2 = typeid(t);
441 // - a new-expression (5.3.4);
442 // - a delete-expression (5.3.5);
443 namespace NewDelete {
446 int n : *new int(4); // expected-error {{constant expression}}
447 int m : (delete p, 2); // expected-error {{constant expression}}
451 // - a relational (5.9) or equality (5.10) operator where the result is
453 namespace UnspecifiedRelations {
455 constexpr int *p = &a, *q = &b;
456 // C++11 [expr.rel]p2: If two pointers p and q of the same type point to
457 // different objects that are not members of the same array or to different
458 // functions, or if only one of them is null, the results of p<q, p>q, p<=q,
459 // and p>=q are unspecified.
460 constexpr bool u1 = p < q; // expected-error {{constant expression}}
461 constexpr bool u2 = p > q; // expected-error {{constant expression}}
462 constexpr bool u3 = p <= q; // expected-error {{constant expression}}
463 constexpr bool u4 = p >= q; // expected-error {{constant expression}}
464 constexpr bool u5 = p < 0; // expected-error {{constant expression}}
465 constexpr bool u6 = p <= 0; // expected-error {{constant expression}}
466 constexpr bool u7 = p > 0; // expected-error {{constant expression}}
467 constexpr bool u8 = p >= 0; // expected-error {{constant expression}}
468 constexpr bool u9 = 0 < q; // expected-error {{constant expression}}
469 constexpr bool u10 = 0 <= q; // expected-error {{constant expression}}
470 constexpr bool u11 = 0 > q; // expected-error {{constant expression}}
471 constexpr bool u12 = 0 >= q; // expected-error {{constant expression}}
474 constexpr void (*pf)() = &f, (*pg)() = &g;
475 constexpr bool u13 = pf < pg; // expected-error {{constant expression}}
476 constexpr bool u14 = pf == pg;
478 // If two pointers point to non-static data members of the same object with
479 // different access control, the result is unspecified.
482 constexpr A() : a(0), b(0) {}
484 constexpr bool cmp() const { return &a < &b; } // expected-error {{constexpr function never produces a constant expression}} expected-note {{comparison of address of fields 'a' and 'b' of 'A' with differing access specifiers (public vs private) has unspecified value}}
491 constexpr bool cmp() const { return &a.a < &b.a; } // expected-error {{constexpr function never produces a constant expression}} expected-note {{comparison of address of fields 'a' and 'b' of 'B' with differing access specifiers (public vs protected) has unspecified value}}
496 // If two pointers point to different base sub-objects of the same object, or
497 // one points to a base subobject and the other points to a member, the result
498 // of the comparison is unspecified. This is not explicitly called out by
499 // [expr.rel]p2, but is covered by 'Other pointer comparisons are
512 constexpr bool base1 = &e.c[0] < &e.d; // expected-error {{constant expression}} expected-note {{comparison of addresses of subobjects of different base classes has unspecified value}}
513 constexpr bool base2 = &e.c[1] < &e.e.f; // expected-error {{constant expression}} expected-note {{comparison of address of base class subobject 'C' of class 'E' to field 'e' has unspecified value}}
514 constexpr bool base3 = &e.e.f < &e.d; // expected-error {{constant expression}} expected-note {{comparison of address of base class subobject 'D' of class 'E' to field 'e' has unspecified value}}
516 // [expr.rel]p3: Pointers to void can be compared [...] if both pointers
517 // represent the same address or are both the null pointer [...]; otherwise
518 // the result is unspecified.
519 struct S { int a, b; } s;
520 constexpr void *null = 0;
521 constexpr void *pv = (void*)&s.a;
522 constexpr void *qv = (void*)&s.b;
523 constexpr bool v1 = null < 0;
524 constexpr bool v2 = null < pv; // expected-error {{constant expression}}
525 constexpr bool v3 = null == pv; // ok
526 constexpr bool v4 = qv == pv; // ok
527 constexpr bool v5 = qv >= pv; // expected-error {{constant expression}} expected-note {{unequal pointers to void}}
528 constexpr bool v6 = qv > null; // expected-error {{constant expression}}
529 constexpr bool v7 = qv <= (void*)&s.b; // ok
530 constexpr bool v8 = qv > (void*)&s.a; // expected-error {{constant expression}} expected-note {{unequal pointers to void}}
533 // - an assignment or a compound assignment (5.17); or
534 namespace Assignment {
537 int n : (k = 9); // expected-error {{constant expression}}
538 int m : (k *= 2); // expected-error {{constant expression}}
542 constexpr Literal(const char *name) : name(name) {}
546 constexpr Expr(Literal l) : IsLiteral(true), l(l) {}
554 constexpr MulEq(Expr a, Expr b) : LHS(a), RHS(b) {}
558 constexpr MulEq operator*=(Expr a, Expr b) { return MulEq(a, b); }
561 MulEq c = a *= b; // ok
564 // - a throw-expression (15.1)
567 int n : (throw "hello", 10); // expected-error {{constant expression}}
572 template<unsigned int v>
573 class bitWidthHolding {
576 unsigned int width = (v == 0 ? 0 : bitWidthHolding<(v >> 1)>::width + 1);
579 static const int width=bitWidthHolding<255>::width;
582 struct always_false {
583 static const bool value = false;
588 static const bool and_value = b && and_or<always_false<b>::value>::and_value;
589 static const bool or_value = !b || and_or<always_false<b>::value>::or_value;
592 static const bool and_value = and_or<true>::and_value;
593 static const bool or_value = and_or<true>::or_value;
595 static_assert(and_value == false, "");
596 static_assert(or_value == true, "");
598 namespace rdar13090123 {
599 typedef __INTPTR_TYPE__ intptr_t;
601 constexpr intptr_t f(intptr_t x) {
602 return (((x) >> 21) * 8); // expected-note{{subexpression not valid in a constant expression}}
607 constexpr intptr_t i = f((intptr_t)&foo - 10); // expected-error{{constexpr variable 'i' must be initialized by a constant expression}} \
608 // expected-note{{in call to 'f((char*)&foo + -10)'}}