YT-22473: Enable for-each formatting in known ranges

5a3405e64b730f0056e381af07658d6c2edcb92b

1 files changed, 73 insertions, 14 deletions

diff --git a/library/cpp/yt/string/format-inl.h b/library/cpp/yt/string/format-inl.h
index 4eaa70bef2..67c8affa6e 100644
--- a/library/cpp/yt/string/format-inl.h
+++ b/library/cpp/yt/string/format-inl.h
@@ -222,24 +222,67 @@ void FormatPointerValue(
 // so that someone doesn't accidentally implement the
 // "SimpleRange" concept and have a non-trivial
 // formatting procedure at the same time.
+// Sadly, clang is bugged and thus we must do implementation by hand
+// if we want to use this concept in class specializations.
 
 template <class R>
-concept CKnownRange =
-    requires (R r) { [] <class... Ts> (std::vector<Ts...>) { } (r); } ||
-    requires (R r) { [] <class T, size_t E> (std::span<T, E>) { } (r); } ||
-    requires (R r) { [] <class T, size_t N> (TCompactVector<T, N>) { } (r); } ||
-    requires (R r) { [] <class... Ts> (std::set<Ts...>) { } (r); } ||
-    requires (R r) { [] <class... Ts> (THashSet<Ts...>) { } (r); } ||
-    requires (R r) { [] <class... Ts> (THashMultiSet<Ts...>) { } (r); };
+constexpr bool CKnownRange = false;
+
+template <class T>
+    requires requires (T* t) { [] <class... Ts> (std::vector<Ts...>*) {} (t); }
+constexpr bool CKnownRange<T> = true;
+template <class T, size_t E>
+constexpr bool CKnownRange<std::span<T, E>> = true;
+template <class T, size_t N>
+constexpr bool CKnownRange<std::array<T, N>> = true;
+template <class T, size_t N>
+constexpr bool CKnownRange<TCompactVector<T, N>> = true;
+template <class T>
+    requires requires (T* t) { [] <class... Ts> (std::set<Ts...>*) {} (t); }
+constexpr bool CKnownRange<T> = true;
+template <class T>
+    requires requires (T* t) { [] <class... Ts> (std::multiset<Ts...>*) {} (t); }
+constexpr bool CKnownRange<T> = true;
+template <class... Ts>
+constexpr bool CKnownRange<THashSet<Ts...>> = true;
+template <class... Ts>
+constexpr bool CKnownRange<THashMultiSet<Ts...>> = true;
 
 ////////////////////////////////////////////////////////////////////////////////
 
 template <class R>
-concept CKnownKVRange =
-    requires (R r) { [] <class... Ts> (std::map<Ts...>) { } (r); } ||
-    requires (R r) { [] <class... Ts> (std::multimap<Ts...>) { } (r); } ||
-    requires (R r) { [] <class... Ts> (THashMap<Ts...>) { } (r); } ||
-    requires (R r) { [] <class... Ts> (THashMultiMap<Ts...>) { } (r); };
+constexpr bool CKnownKVRange = false;
+
+template <class T>
+    requires requires (T* t) { [] <class... Ts> (std::map<Ts...>*) {} (t); }
+constexpr bool CKnownKVRange<T> = true;
+template <class T>
+    requires requires (T* t) { [] <class... Ts> (std::multimap<Ts...>*) {} (t); }
+constexpr bool CKnownKVRange<T> = true;
+template <class... Ts>
+constexpr bool CKnownKVRange<THashMap<Ts...>> = true;
+template <class... Ts>
+constexpr bool CKnownKVRange<THashMultiMap<Ts...>> = true;
+
+// TODO(arkady-e1ppa): Uncomment me when
+// https://github.com/llvm/llvm-project/issues/58534 is shipped.
+// template <class R>
+// concept CKnownRange =
+//     requires (R r) { [] <class... Ts> (std::vector<Ts...>) { } (r); } ||
+//     requires (R r) { [] <class T, size_t E> (std::span<T, E>) { } (r); } ||
+//     requires (R r) { [] <class T, size_t N> (TCompactVector<T, N>) { } (r); } ||
+//     requires (R r) { [] <class... Ts> (std::set<Ts...>) { } (r); } ||
+//     requires (R r) { [] <class... Ts> (THashSet<Ts...>) { } (r); } ||
+//     requires (R r) { [] <class... Ts> (THashMultiSet<Ts...>) { } (r); };
+
+// ////////////////////////////////////////////////////////////////////////////////
+
+// template <class R>
+// concept CKnownKVRange =
+//     requires (R r) { [] <class... Ts> (std::map<Ts...>) { } (r); } ||
+//     requires (R r) { [] <class... Ts> (std::multimap<Ts...>) { } (r); } ||
+//     requires (R r) { [] <class... Ts> (THashMap<Ts...>) { } (r); } ||
+//     requires (R r) { [] <class... Ts> (THashMultiMap<Ts...>) { } (r); };
 
 } // namespace NDetail
 
@@ -300,6 +343,22 @@ concept CFormattableKVRange =
     CFormattable<typename R::key_type> &&
     CFormattable<typename R::value_type>;
 
+
+////////////////////////////////////////////////////////////////////////////////
+
+// Specializations of TFormatArg for ranges
+template <class R>
+    requires CFormattableRange<std::remove_cvref_t<R>>
+struct TFormatArg<R>
+    : public TFormatArgBase
+{
+    using TUnderlying = typename std::remove_cvref_t<R>::value_type;
+
+    static constexpr auto ConversionSpecifiers = TFormatArg<TUnderlying>::ConversionSpecifiers;
+
+    static constexpr auto FlagSpecifiers = TFormatArg<TUnderlying>::FlagSpecifiers;
+};
+
 ////////////////////////////////////////////////////////////////////////////////
 
 template <class TRange, class TFormatter>
@@ -740,9 +799,9 @@ void FormatValue(TStringBuilderBase* builder, const TEnumIndexedArray<E, T>& col
 
 // One-valued ranges
 template <CFormattableRange TRange>
-void FormatValue(TStringBuilderBase* builder, const TRange& collection, TStringBuf /*spec*/)
+void FormatValue(TStringBuilderBase* builder, const TRange& collection, TStringBuf spec)
 {
-    NYT::FormatRange(builder, collection, TDefaultFormatter());
+    NYT::FormatRange(builder, collection, TSpecBoundFormatter(spec));
 }
 
 // Two-valued ranges