File: cxx2a-constraint-caching.cpp

package info (click to toggle)
llvm-toolchain-14 1%3A14.0.6-16
  • links: PTS, VCS
  • area: main
  • in suites: sid
  • size: 1,496,368 kB
  • sloc: cpp: 5,593,980; ansic: 986,873; asm: 585,869; python: 184,223; objc: 72,530; lisp: 31,119; f90: 27,793; javascript: 9,780; pascal: 9,762; sh: 9,482; perl: 7,468; ml: 5,432; awk: 3,523; makefile: 2,547; xml: 953; cs: 573; fortran: 567
file content (34 lines) | stat: -rw-r--r-- 816 bytes parent folder | download | duplicates (6) 
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
 
// RUN:  %clang_cc1 -std=c++2a -verify %s
// RUN:  %clang_cc1 -std=c++2a -verify %s -fno-concept-satisfaction-caching -DNO_CACHE
// expected-no-diagnostics

template<typename T>
concept C = (f(T()), true);

template<typename T>
constexpr bool foo() { return false; }

template<typename T>
  requires (f(T()), true)
constexpr bool foo() requires (f(T()), true) { return true; }

namespace a {
  struct A {};
  constexpr void f(A a) {}
}

static_assert(C<a::A>);
static_assert(foo<a::A>());

namespace a {
  // This makes calls to f ambiguous, but the second check will still succeed
  // because the constraint satisfaction results are cached.
  constexpr void f(A a, int = 2) {}
}
#ifdef NO_CACHE
static_assert(!C<a::A>);
static_assert(!foo<a::A>());
#else
static_assert(C<a::A>);
static_assert(foo<a::A>());
#endif