File: cxx1z-decomposition.cpp

package info (click to toggle)
llvm-toolchain-13 1%3A13.0.1-6~deb10u4
  • links: PTS, VCS
  • area: main
  • in suites: buster
  • size: 1,418,792 kB
  • sloc: cpp: 5,290,827; ansic: 996,570; asm: 544,593; python: 188,212; objc: 72,027; lisp: 30,291; f90: 25,395; sh: 24,900; javascript: 9,780; pascal: 9,398; perl: 7,484; ml: 5,432; awk: 3,523; makefile: 2,892; xml: 953; cs: 573; fortran: 539
file content (33 lines) | stat: -rw-r--r-- 876 bytes parent folder | download | duplicates (35) 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
 
// RUN: %clang_cc1 -std=c++1z -verify %s

struct A { int x, y; };
typedef int B[2];
struct C { template<int> int get(); };
struct D { int x, y, z; };
struct E { int *p, n; };

namespace std {
  using size_t = decltype(sizeof(0));
  template<typename> struct tuple_size;
  template<size_t, typename> struct tuple_element { using type = int; };
}

template<> struct std::tuple_size<C> { enum { value = 2 }; };

template<typename T> int decomp(T &t) { 
  auto &[a, b] = t; // expected-error {{type 'D' decomposes into 3 elements, but only 2 names were provided}}
  return a + b; // expected-error {{cannot initialize return object of type 'int' with an rvalue of type 'int *'}}
}

void test() {
  A a;
  B b;
  C c;
  D d;
  E e;
  decomp(a);
  decomp(b);
  decomp(c);
  decomp(d); // expected-note {{in instantiation of}}
  decomp(e); // expected-note {{in instantiation of}}
}