xref: /llvm-project/clang/test/CXX/expr/expr.const/p8-2a.cpp (revision d0db54e0dd3272a044407a6394cae47c84cd3a70)
1e328d68dSAaron Ballman // RUN: %clang_cc1 -std=c++20 -verify %s
2e328d68dSAaron Ballman 
3e328d68dSAaron Ballman // expected-no-diagnostics
4e328d68dSAaron Ballman 
5*d0db54e0SMariya Podchishchaeva namespace P1937R2 {
6e328d68dSAaron Ballman struct N {
NP1937R2::N7e328d68dSAaron Ballman   constexpr N() {}
8e328d68dSAaron Ballman   N(N const&) = delete;
9e328d68dSAaron Ballman };
10e328d68dSAaron Ballman 
bad_assert_copyable()11e328d68dSAaron Ballman template<typename T> constexpr void bad_assert_copyable() { T t; T t2 = t; }
12e328d68dSAaron Ballman using ineffective = decltype(bad_assert_copyable<N>());
13e328d68dSAaron Ballman 
assert_copyable()14e328d68dSAaron Ballman template<typename T> consteval void assert_copyable() { T t; T t2 = t; }
15*d0db54e0SMariya Podchishchaeva // Prior to P1937R2 consteval functions were evaluated even in otherwise
16*d0db54e0SMariya Podchishchaeva // unevaluated context, now this is well-formed.
17e328d68dSAaron Ballman using check = decltype(assert_copyable<N>());
18*d0db54e0SMariya Podchishchaeva 
19*d0db54e0SMariya Podchishchaeva template<typename T>
20*d0db54e0SMariya Podchishchaeva __add_rvalue_reference(T) declval();
21*d0db54e0SMariya Podchishchaeva 
add1(auto lhs,auto rhs)22*d0db54e0SMariya Podchishchaeva constexpr auto add1(auto lhs, auto rhs) {
23*d0db54e0SMariya Podchishchaeva     return lhs + rhs;
24*d0db54e0SMariya Podchishchaeva }
25*d0db54e0SMariya Podchishchaeva using T = decltype(add1(declval<int>(), declval<int>()));
26*d0db54e0SMariya Podchishchaeva 
add2(auto lhs,auto rhs)27*d0db54e0SMariya Podchishchaeva consteval auto add2(auto lhs, auto rhs) {
28*d0db54e0SMariya Podchishchaeva     return lhs + rhs;
29*d0db54e0SMariya Podchishchaeva }
30*d0db54e0SMariya Podchishchaeva using T = decltype(add2(declval<int>(), declval<int>()));
31*d0db54e0SMariya Podchishchaeva } // namespace P1937R2
32e328d68dSAaron Ballman 
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