clang/test/CXX/expr/expr.prim/expr.prim.lambda/p13.cpp

   1 // RUN: %clang_cc1 -std=c++11 %s -Wunused -Wno-unused-lambda-capture -Wno-c++14-extensions -verify
   2 // RUN: %clang_cc1 -std=c++17 %s -Wunused -Wno-unused-lambda-capture -Wno-c++14-extensions -verify
   3
   4
   5 const int global = 0;
   6
   7 void f2() {
   8   int i = 1;
   9   void g1(int = ([i]{ return i; })()); // expected-error{{lambda expression in default argument cannot capture any entity}}
  10   void g2(int = ([i]{ return 0; })()); // expected-error{{lambda expression in default argument cannot capture any entity}}
  11   void g3(int = ([=]{ return i; })()); // expected-error{{lambda expression in default argument cannot capture any entity}}
  12   void g4(int = ([=]{ return 0; })());
  13   void g5(int = ([]{ return sizeof i; })());
  14   void g6(int = ([x=1, y = global, &z = global]{ return x; })());
  15   void g7(int = ([x=i, &y=i]{ return x; })()); // expected-error 2{{default argument references local variable 'i' of enclosing function}}
  16 }
  17
  18 #if __cplusplus >= 201703L
  19 int global_array[] = { 1, 2 };
  20 auto [ga, gb] = global_array;
  21
  22 void structured_bindings() {
  23   int array[] = { 1, 2 };
  24   auto [a, b] = array;
  25   void func(int c = [x = a, &xref = a, y = ga, &yref = ga] { return x; }()); // expected-error 2{{default argument references local variable 'a' of enclosing function}}
  26 }
  27 #endif
  28
  29 namespace lambda_in_default_args {
  30   int f(int = [] () -> int { int n; return ++n; } ());
  31   template<typename T> T g(T = [] () -> T { T n; return ++n; } ());
  32   int k = f() + g<int>();
  33 }