1 // RUN: %clang_cc1 -std=c++17 -fsyntax-only -verify %s
2 
3 // expected-no-diagnostics
4 
5 // Check recursive instantiation of lambda does not cause assertion.
6 // lambda function `f` in `fun1` is instantiated twice: first
7 // as f(f, Number<1>), then as f(f, Number<0>). The
8 // LocalInstantiationScopes of these two instantiations both contain
9 // `f` and `i`. However, since they are not merged, clang should not
10 // assert for that.
11 
12 template <unsigned v>
13 struct Number
14 {
15    static constexpr unsigned value = v;
16 };
17 
18 template <unsigned IBegin = 0,
19           unsigned IEnd = 1>
20 constexpr auto fun1(Number<IBegin> = Number<0>{}, Number<IEnd>  = Number<1>{})
21 {
22   constexpr unsigned a = 0;
23   auto f = [&](auto fs, auto i) {
24     if constexpr(i.value > 0)
25     {
26       (void)a;
27       return fs(fs, Number<IBegin>{});
28     }
29     (void)a;
30   };
31 
32   return f(f, Number<IEnd>{});
33 }
34 
35 
36 void fun2() {
37   fun1();
38 }
39