File: lambda-conv2.C

package info (click to toggle)
gcc-arm-none-eabi 15%3A14.2.rel1-1
  • links: PTS, VCS
  • area: main
  • in suites: forky, sid, trixie
  • size: 1,099,328 kB
  • sloc: cpp: 3,627,108; ansic: 2,571,498; ada: 834,230; f90: 235,082; makefile: 79,231; asm: 74,984; xml: 51,692; exp: 39,736; sh: 33,298; objc: 15,629; python: 15,069; fortran: 14,429; pascal: 7,003; awk: 5,070; perl: 3,106; ml: 285; lisp: 253; lex: 204; haskell: 135
file content (23 lines) | stat: -rw-r--r-- 625 bytes parent folder | download | duplicates (6) 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
 
// PR c++/71105
// { dg-do compile { target c++14 } }

template <typename T> T declval();
template <typename, typename> struct is_same
{ static constexpr bool value = false; };
template <typename T> struct is_same<T, T>
{ static constexpr bool value = true; };

template <class F>
struct indirected : F {
  indirected(F f) : F(f) {}
  template <class I>
  auto operator()(I i) -> decltype(declval<F&>()(*i)) {
    return static_cast<F&>(*this)(*i);
  }
};

int main() {
  auto f = [=](auto i) { return i + i; };
  auto i = indirected<decltype(f)>{f};
  static_assert(is_same<decltype(i(declval<int*>())), int>::value, "");
}