clang/test/CodeGenCXX/mangle-requires.cpp

// RUN: %clang_cc1 -verify -std=c++2a -fclang-abi-compat=latest -emit-llvm -triple %itanium_abi_triple -o - %s | FileCheck %s
// expected-no-diagnostics

template <typename T, int N> concept SmallerThan = sizeof(T) < N;
template <typename T> concept Small = SmallerThan<T, 1000>;

template <typename T> struct X { using type = T; };

template <typename T> void f(int n) requires requires {
  // simple-requirement
  T();
  n;
  n == T();
  // compound-requirement
  {T() + 1} -> Small;
  {T() - 1} noexcept;
  {T() * 2} noexcept -> SmallerThan<1234>;
  // type-requirement
  typename T;
  typename X<T>;
  typename X<T>::type;
  typename X<decltype(n)>;
  // nested-requirement
  requires SmallerThan<T, 256>;
} {}
// CHECK: define {{.*}}@_Z1fIiEviQrqXcvT__EXfp_Xeqfp_cvS0__EXplcvS0__ELi1ER5SmallXmicvS0__ELi1ENXmlcvS0__ELi2ENR11SmallerThanILi1234EETS0_T1XIS0_ETNS3_4typeETS2_IiEQ11SmallerThanIS0_Li256EEE(
template void f<int>(int);

template <typename T> void g(int n) requires requires (T m) {
  // reference to our parameter vs an enclosing parameter
  n + m;
} {}
// CHECK: define {{.*}}@_Z1gIiEviQrQT__XplfL0p_fp_E(
template void g<int>(int);


namespace GH147650 {

template <int> int b;
template <int b>
void f()
    requires requires { [] { (void)b; }; } {}
void test() {
    f<42>();
}
// CHECK-LABEL:define {{.*}} void @"_ZN8GH1476501fILi42EEEvvQrqXLNS_3$_0EEE"()
}

namespace GH123854
{

template <class T>
constexpr auto f() {
  return [] () requires requires (T x) { x; } {};
}

void test() {
  f<int>()();
}
// CHECK-LABEL:define {{.*}} void @_ZZN8GH1238541fIiEEDavENKUlvE_clEvQrQT__Xfp_E
}

namespace GH100774 {

void test_dependent() {
  auto L = [](auto x) {
    return [w = x](auto) requires requires { w; } {};
  };
  L(0)(1);
}
// CHECK-LABEL: define internal void @"_ZZZN8GH10077414test_dependentEvENK3$_0clIiEEDaT_ENKUlS2_E_clIiEEDaS2_QrqXL_ZZZNS_14test_dependentEvENKS0_clES2_E1wEE"
}