File: decltype5.C

package info (click to toggle)
gcc-arm-none-eabi 15%3A8-2019-q3-1
  • links: PTS, VCS
  • area: main
  • in suites: bullseye
  • size: 571,828 kB
  • sloc: ansic: 2,937,651; cpp: 881,644; ada: 597,189; makefile: 65,528; asm: 56,499; xml: 46,621; exp: 24,747; sh: 19,684; python: 7,256; pascal: 4,370; awk: 3,497; perl: 2,695; yacc: 316; ml: 285; f90: 234; lex: 198; objc: 194; haskell: 119
file content (37 lines) | stat: -rw-r--r-- 717 bytes parent folder | download | duplicates (10) 
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
34
35
36
37
 
// { dg-do compile { target c++11 } }

template<typename T, typename U> 
struct is_same 
{
  static const bool value = false;
};

template<typename T>
struct is_same<T, T>
{
  static const bool value = true;
};

#define CHECK_DECLTYPE(DECLTYPE,RESULT) \
  static_assert(is_same< DECLTYPE , RESULT >::value, #RESULT)

template<typename F> F create_a();

template<typename F, typename T1>
decltype(create_a<F&>()(create_a<const T1&>())) forward(F f, const T1& a1)
{
  return f(a1);
}

struct identity {
  template<typename T>
  const T& operator()(const T& x) { return x; }
};


identity id;
int i;
float f;

CHECK_DECLTYPE(decltype(forward(id, i)), const int&);
CHECK_DECLTYPE(decltype(forward(id, f)), const float&);