File: cxx2a-constraint-exprs.cpp

package info (click to toggle)
llvm-toolchain-15 1%3A15.0.6-4
  • links: PTS, VCS
  • area: main
  • in suites: bookworm
  • size: 1,554,644 kB
  • sloc: cpp: 5,922,452; ansic: 1,012,136; asm: 674,362; python: 191,568; objc: 73,855; f90: 42,327; lisp: 31,913; pascal: 11,973; javascript: 10,144; sh: 9,421; perl: 7,447; ml: 5,527; awk: 3,523; makefile: 2,520; xml: 885; cs: 573; fortran: 567
file content (53 lines) | stat: -rw-r--r-- 2,900 bytes parent folder | download | duplicates (9)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
// RUN:  %clang_cc1 -std=c++2a -verify %s

// Make sure constraint expressions are unevaluated before being substituted
// into during satisfaction checking.

template<typename T> constexpr bool f = T::value;
// expected-error@-1 4{{type}}

namespace unevaluated {
  template<typename T> concept Foo = false && f<int>;
  bool k = Foo<int>;
  template<typename T> requires false && f<int> struct S {};
  // expected-note@-1{{because}}
  using s = S<int>; // expected-error {{constraints not satisfied}}
  template<typename T> void foo() requires false && f<int> { };
  // expected-note@-1{{because}} expected-note@-1{{candidate template ignored}}
  int a = (foo<int>(), 0); // expected-error{{no matching function}}
  template<typename T> void bar() requires requires { requires false && f<int>; } { };
  // expected-note@-1{{because}} expected-note@-1{{candidate template ignored}}
  int b = (bar<int>(), 0); // expected-error{{no matching function}}
  template<typename T> struct M { static void foo() requires false && f<int> { }; };
  // expected-note@-1{{because}}
  int c = (M<int>::foo(), 0);
  // expected-error@-1{{invalid reference to function 'foo': constraints not satisfied}}
}

namespace constant_evaluated {
  template<typename T> requires f<int[0]> struct S {};
  // expected-note@-1{{in instantiation of}} expected-note@-1{{while substituting}} \
     expected-error@-1{{substitution into constraint expression resulted in a non-constant expression}} \
     expected-note@-1{{subexpression not valid}}
  using s = S<int>;
  // expected-note@-1 2{{while checking}}
  template<typename T> void foo() requires f<int[1]> { };
  // expected-note@-1{{in instantiation}} expected-note@-1{{while substituting}} \
     expected-note@-1{{candidate template ignored}} expected-note@-1{{subexpression not valid}} \
     expected-error@-1{{substitution into constraint expression resulted in a non-constant expression}}
  int a = (foo<int>(), 0);
  // expected-note@-1 2{{while checking}} expected-error@-1{{no matching function}} \
     expected-note@-1 2{{in instantiation}}
  template<typename T> void bar() requires requires { requires f<int[2]>; } { };
  // expected-note@-1{{in instantiation}} expected-note@-1{{subexpression not valid}} \
     expected-note@-1{{while substituting}} \
     expected-error@-1{{substitution into constraint expression resulted in a non-constant expression}} \
     expected-note@-1 2{{while checking the satisfaction of nested requirement}}
  int b = (bar<int>(), 0);
  template<typename T> struct M { static void foo() requires f<int[3]> { }; };
  // expected-note@-1{{in instantiation}} expected-note@-1{{subexpression not valid}} \
     expected-note@-1{{while substituting}} \
     expected-error@-1{{substitution into constraint expression resulted in a non-constant expression}}
  int c = (M<int>::foo(), 0);
  // expected-note@-1 2{{while checking}}
}