[gcc r15-7546] c++: add fixed test [PR83144]

[Marek Polacek via Gcc-cvs]

https://gcc.gnu.org/g:8e44f7ecb7b9ad6893f7784b1a303a5463b46cd5

commit r15-7546-g8e44f7ecb7b9ad6893f7784b1a303a5463b46cd5
Author: Marek Polacek <pola...@redhat.com>
Date:   Fri Feb 14 17:29:27 2025 -0500

    c++: add fixed test [PR83144]
    
    Fixed by r12-4425 and it seemed worth adding.
    
            PR c++/83144
    
    gcc/testsuite/ChangeLog:
    
            * g++.dg/cpp0x/constexpr-83144.C: New test.

Diff:
---
 gcc/testsuite/g++.dg/cpp0x/constexpr-83144.C | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/gcc/testsuite/g++.dg/cpp0x/constexpr-83144.C 
b/gcc/testsuite/g++.dg/cpp0x/constexpr-83144.C
new file mode 100644
index 000000000000..858fec13a2c8
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/constexpr-83144.C
@@ -0,0 +1,21 @@
+// PR c++/83144
+// { dg-do compile { target c++11 } }
+
+template <typename...> class tuple;
+struct _Head_base {
+  int _M_head_impl;
+};
+template <unsigned long, typename...> struct _Tuple_impl;
+template <unsigned long _Idx, typename _Head, typename... _Tail>
+struct _Tuple_impl<_Idx, _Head, _Tail...> : _Head_base {};
+template <typename _T1, typename _T2>
+struct tuple<_T1, _T2> : _Tuple_impl<0, _T2> {
+  template <typename _U1, typename _U2> tuple(_U1, _U2);
+};
+template <long, typename... _Elements> void get(tuple<_Elements...>);
+template <class T> struct interval_t : tuple<T, T> {
+  using tuple<T, T>::tuple;
+  constexpr T last() { get<1>(*this); }
+  auto size() -> decltype(last() - 0);
+};
+int main(int argc, char **) { interval_t<int>{2, argc}; }