clang/test/Parser/lambda-misplaced-capture-default.cpp

   1 // RUN: %clang_cc1 -std=c++20 -Wno-unused-value -fsyntax-only -verify %s
   2
   3 namespace misplaced_capture_default {
   4 void Test() {
   5   int i = 0;
   6   [&, i, &] {};   // expected-error {{expected variable name or 'this' in lambda capture list}}
   7   [&, i, = ] {};  // expected-error {{expected variable name or 'this' in lambda capture list}}
   8   [=, &i, &] {};  // expected-error {{expected variable name or 'this' in lambda capture list}}
   9   [=, &i, = ] {}; // expected-error {{expected variable name or 'this' in lambda capture list}}
  10
  11   [i, &] {};   // expected-error {{capture default must be first}}
  12   [i, = ] {};  // expected-error {{capture default must be first}}
  13   [i, = x] {}; // expected-error {{expected variable name or 'this' in lambda capture list}}
  14   [=, &i] {};  // ok
  15   [&, &i] {};  // expected-error {{'&' cannot precede a capture when the capture default is '&'}}
  16   [&x = i] {}; // ok
  17   [=, &x = i] {};  // ok
  18   [x = &i] {};     // ok
  19   [=, &x = &i] {}; // expected-error {{non-const lvalue reference to type 'int *' cannot bind to a temporary of type 'int *'}}
  20   [&, this] {}; // expected-error {{'this' cannot be captured in this context}}
  21
  22   [i, &, x = 2] {}; // expected-error {{capture default must be first}}
  23   [i, =, x = 2] {}; // expected-error {{capture default must be first}}
  24 }
  25 } // namespace misplaced_capture_default
  26
  27 namespace misplaced_capture_default_pack {
  28 template <typename... Args> void Test(Args... args) {
  29   [&, args...] {};         // ok
  30   [args..., &] {};         // expected-error {{capture default must be first}}
  31   [=, &args...] {};        // ok
  32   [&, ... xs = &args] {};  // ok
  33   [&, ... xs = &] {};      // expected-error {{expected expression}}
  34   [... xs = &] {};         // expected-error {{expected expression}}
  35   [... xs = &args, = ] {}; // expected-error {{capture default must be first}}
  36   [... xs = &args, &] {};  // expected-error {{capture default must be first}}
  37 }
  38 } // namespace misplaced_capture_default_pack