171 lines · cpp
1// RUN: %clang_cc1 -std=c++2a -x c++ %s -verify2 3bool r1 = requires () {};4// expected-error@-1 {{a requires expression must contain at least one requirement}}5 6bool r2 = requires { requires true; };7 8bool r3 = requires (int a, ...) { requires true; };9// expected-error@-1 {{varargs not allowed in requires expression}}10 11template<typename... T>12bool r4 = requires (T... ts) { requires true; };13 14bool r5 = requires (bool c, int d) { c; d; };15 16bool r6 = requires (bool c, int d) { c; d; } && decltype(d){};17// expected-error@-1 {{use of undeclared identifier 'd'}}18 19bool r7 = requires (bool c) { c; (requires (int d) { c; d; }); d; } && decltype(c){} && decltype(d){};20// expected-error@-1 2{{use of undeclared identifier 'd'}}21// expected-error@-2 {{use of undeclared identifier 'c'}}22 23bool r8 = requires (bool, int) { requires true; };24 25bool r9 = requires (bool a, int a) { requires true; };26// expected-error@-1 {{redefinition of parameter 'a'}}27// expected-note@-2 {{previous declaration is here}}28 29bool r10 = requires (struct new_struct { int x; } s) { requires true; };30// expected-error@-1 {{'new_struct' cannot be defined in a parameter type}}31 32bool r11 = requires (int x(1)) { requires true; };33// expected-error@-1 {{expected parameter declarator}}34// expected-error@-2 {{expected ')'}}35// expected-note@-3 {{to match this '('}}36 37bool r12 = requires (int x = 10) { requires true; };38// expected-error@-1 {{default arguments not allowed for parameters of a requires expression}}39 40bool r13 = requires (int f(int)) { requires true; };41 42bool r14 = requires (int (*f)(int)) { requires true; };43 44bool r15 = requires (10) { requires true; };45// expected-error@-1 {{expected parameter declarator}}46// expected-error@-2 {{expected ')'}} expected-note@-2 {{to match}}47 48bool r16 = requires (auto x) { requires true; };49// expected-error@-1 {{'auto' not allowed in requires expression parameter}}50 51bool r17 = requires (auto [x, y]) { requires true; };52// expected-error@-1 {{'auto' not allowed in requires expression parameter}}53// expected-error@-2 {{use of undeclared identifier 'x'}}54 55using a = int;56 57bool r18 = requires { typename a; };58 59bool r19 = requires { typename ::a; };60 61template<typename T> struct identity { using type = T; };62 63template<typename T> using identity_t = T;64 65bool r20 = requires {66 typename identity<int>::type;67 typename identity<int>;68 typename ::identity_t<int>;69};70 71struct s { bool operator==(const s&); ~s(); };72 73bool r21 = requires { typename s::operator==; };74// expected-error@-1 {{expected an identifier or template-id after '::'}}75 76bool r22 = requires { typename s::~s; };77// expected-error@-1 {{expected an identifier or template-id after '::'}}78 79template<typename T>80bool r23 = requires { typename identity<T>::temp<T>; };81// expected-error@-1 {{use 'template' keyword to treat 'temp' as a dependent template name}}82 83template<typename T>84bool r24 = requires {85 typename identity<T>::template temp<T>;86 typename identity<T>::template temp; // expected-error{{template argument list is expected after a name prefixed by the template keyword}}87};88 89bool r25 = requires { ; };90// expected-error@-1 {{expected expression}}91 92bool r26 = requires { {}; };93// expected-error@-1 {{expected expression}}94 95bool r27 = requires { { 0 } noexcept; };96 97bool r28 = requires { { 0 } noexcept noexcept; };98// expected-error@-1 {{expected '->' before expression type requirement}}99// expected-error@-2 {{expected concept name with optional arguments}}100 101template<typename T>102concept C1 = true;103 104template<typename T, typename U>105concept C2 = true;106 107bool r29 = requires { { 0 } noexcept C1; };108// expected-error@-1 {{expected '->' before expression type requirement}}109 110bool r30 = requires { { 0 } noexcept -> C2<int>; };111 112namespace ns { template<typename T> concept C = true; }113 114bool r31 = requires { { 0 } noexcept -> ns::C; };115 116template<typename T>117T i1 = 0;118 119bool r32 = requires { requires false, 1; };120// expected-error@-1 {{expected ';' at end of requirement}}121 122bool r33 = requires { 0 noexcept; };123// expected-error@-1 {{'noexcept' can only be used in a compound requirement (with '{' '}' around the expression)}}124 125bool r34 = requires { 0 int; };126// expected-error@-1 {{expected ';' at end of requirement}}127 128bool r35 = requires { requires true };129// expected-error@-1 {{expected ';' at end of requirement}}130 131bool r36 = requires (bool b) { requires sizeof(b) == 1; };132 133template<typename T>134void r37(bool b) requires requires { 1 } {}135// expected-error@-1 {{expected ';' at end of requirement}}136 137bool r38 = requires { requires { 1; }; };138// expected-error@-1 {{requires expression in requirement body; did you intend to place it in a nested requirement? (add another 'requires' before the expression)}}139 140bool r39 = requires { requires () { 1; }; };141// expected-error@-1 {{requires expression in requirement body; did you intend to place it in a nested requirement? (add another 'requires' before the expression)}}142 143bool r40 = requires { requires (int i) { i; }; };144// expected-error@-1 {{requires expression in requirement body; did you intend to place it in a nested requirement? (add another 'requires' before the expression)}}145 146bool r41 = requires { requires (); };147// expected-error@-1 {{expected expression}}148 149bool r42 = requires { typename long; }; // expected-error {{expected a qualified name after 'typename'}}150 151template <int N>152requires requires {153 typename _BitInt(N); // expected-error {{expected a qualified name after 'typename'}}154} using r43 = void;155 156template <int N>157using BitInt = _BitInt(N);158 159template <int N>160requires requires {161 typename BitInt<N>; // ok162} using r44 = void;163 164namespace GH73112 {165void f() {166 requires { requires(int; } // expected-error {{expected ')'}} \167 // expected-error {{expected expression}} \168 // expected-note {{to match this '('}}169}170}171