clang/test/PCH/cxx2a-template-lambdas.cpp

   1 // RUN: %clang_cc1 -std=c++2a -emit-pch %s -o %t
   2 // RUN: %clang_cc1 -std=c++2a -include-pch %t -verify %s
   3
   4 // RUN: %clang_cc1 -std=c++2a -emit-pch -fpch-instantiate-templates %s -o %t
   5 // RUN: %clang_cc1 -std=c++2a -include-pch %t -verify %s
   6
   7 // expected-no-diagnostics
   8
   9 #ifndef HEADER
  10 #define HEADER
  11
  12 auto l1 = []<int I>() constexpr -> int {
  13     return I;
  14 };
  15
  16 auto l2 = []<auto I>() constexpr -> decltype(I) {
  17     return I;
  18 };
  19
  20 auto l3 = []<class T>(auto i) constexpr -> T {
  21   return T(i);
  22 };
  23
  24 auto l4 = []<template<class> class T, class U>(T<U>, auto i) constexpr -> U {
  25   return U(i);
  26 };
  27
  28 #else /*included pch*/
  29
  30 static_assert(l1.operator()<5>() == 5);
  31 static_assert(l1.operator()<6>() == 6);
  32
  33 static_assert(l2.operator()<7>() == 7);
  34 static_assert(l2.operator()<nullptr>() == nullptr);
  35
  36 static_assert(l3.operator()<int>(8.4) == 8);
  37 static_assert(l3.operator()<int>(9.9) == 9);
  38
  39 template<typename T>
  40 struct DummyTemplate { };
  41
  42 static_assert(l4(DummyTemplate<float>(), 12) == 12.0);
  43 static_assert(l4(DummyTemplate<int>(), 19.8) == 19);
  44
  45 #endif // HEADER