This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 115d. See http://www.open-std.org/jtc1/sc22/wg21/ for the official list.

2024-10-26

1631. Incorrect overload resolution for single-element initializer-list

[Moved to DR at the November, 2014 meeting.]

According to bullet 1 of 12.2.4.2.6 [over.ics.list] paragraph 6,

Otherwise, if the parameter type is not a class:

• if the initializer list has one element, the implicit conversion sequence is the one required to convert the element to the parameter type;

• ...

This wording ignores the possibility that the element might be an initializer list (as opposed to an expression with a type, as illustrated in the example). This oversight affects an example like:

  struct A { int a[1]; };
  struct B { B(int); };
  void f(B, int);
  void f(int, A);

  int main() {
    f({0}, {{1}});
  }

Proposed resolution (June, 2014):

This issue is resolved by the resolution of issue 1467.