[clang] [Sema][CTAD] Allow user defined conversion for copy-list-initialization (PR #94752)

[Younan Zhang via cfe-commits]

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@@ -0,0 +1,90 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -Wno-unused-value -std=c++20 %s
+namespace std
+{
+  typedef long unsigned int size_t;
+}
+
+namespace std
+{
+  template<class _E>
+    class initializer_list
+    {
+    public:
+      typedef _E value_type;
+      typedef const _E& reference;
+      typedef const _E& const_reference;
+      typedef size_t size_type;
+      typedef const _E* iterator;
+      typedef const _E* const_iterator;
+
+    private:
+      iterator _M_array;
+      size_type _M_len;
+
+
+      constexpr initializer_list(const_iterator __a, size_type __l)
+      : _M_array(__a), _M_len(__l) { }
+
+    public:
+      constexpr initializer_list() noexcept
+      : _M_array(0), _M_len(0) { }
+
+
+      constexpr size_type
+      size() const noexcept { return _M_len; }
+
+
+      constexpr const_iterator
+      begin() const noexcept { return _M_array; }
+
+
+      constexpr const_iterator
+      end() const noexcept { return begin() + size(); }
+    };
+
+  template<class _Tp>
+    constexpr const _Tp*
+    begin(initializer_list<_Tp> __ils) noexcept
+    { return __ils.begin(); }
+
+  template<class _Tp>
+    constexpr const _Tp*
+    end(initializer_list<_Tp> __ils) noexcept
+    { return __ils.end(); }
+}
+
+template<class T, class Y>
+class pair{
+    private:
+    T fst;
+    Y snd;
+    public:
+    pair(T f, Y s) : fst(f), snd(s) {}
+};
+
+template<class T, class Y>
+class map {
+    public:
+    map(std::initializer_list<pair<T, Y>>, int a = 4, int b = 5) {}
+};
+
+template<class T, class Y>
+class Contained {
+  public:
+  Contained(T, Y) {}
+};
+
+template<class T, class Y>
+class A {
+  public:
+  A(std::initializer_list<Contained<T, Y> >, int) {}
+};
+
+int main() {
+    map mOk ={pair{5, 'a'}, {6, 'b'}, {7, 'c'}};
----------------
zyn0217 wrote:

Could you try to simplify the test case a bit? There is so much boilerplate that it's hard to understand the issue.

https://github.com/llvm/llvm-project/pull/94752