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 Ballmantemplate<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 Ballmantemplate<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 Podchishchaevaconstexpr 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 Podchishchaevaconsteval 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 33