Fixing compilation on GCC 11.x

include/mdcomp/stream_utils.hh

@@ -177,6 +177,19 @@ namespace detail {
 
  template <typename Fn, typename... Types>
  class range_closure : public pipe::base<range_closure<Fn, Types...>> {
+ private:
+ template <typename SelfTy, typename Ty, size_t... Idx>
+ constexpr static decltype(auto)
+ call(SelfTy&& self, Ty&& arg, std::index_sequence<Idx...>) noexcept(
+ noexcept(Fn{}(
+ std::forward<Ty>(arg),
+ std::get<Idx>(std::forward<SelfTy>(self).captures)...))) {
+ static_assert(std::same_as<std::index_sequence<Idx...>, indices>);
+ return Fn{}(
+ std::forward<Ty>(arg),
+ std::get<Idx>(std::forward<SelfTy>(self).captures)...);
+ }
+
  public:
  // We assume that Fn is the type of a customization point object. That means
  // 1. The behavior of operator() is independent of cvref qualifiers, so we can use
@@ -231,18 +244,6 @@ namespace detail {
  }
 
  private:
- template <typename SelfTy, typename Ty, size_t... Idx>
- constexpr static decltype(auto)
- call(SelfTy&& self, Ty&& arg, std::index_sequence<Idx...>) noexcept(
- noexcept(Fn{}(
- std::forward<Ty>(arg),
- std::get<Idx>(std::forward<SelfTy>(self).captures)...))) {
- static_assert(std::same_as<std::index_sequence<Idx...>, indices>);
- return Fn{}(
- std::forward<Ty>(arg),
- std::get<Idx>(std::forward<SelfTy>(self).captures)...);
- }
-
  std::tuple<Types...> captures;
  };