diff --git a/clang/lib/Sema/SemaConcept.cpp b/clang/lib/Sema/SemaConcept.cpp
index 2882b10613fdc..4e7033c9d588d 100644
--- a/clang/lib/Sema/SemaConcept.cpp
+++ b/clang/lib/Sema/SemaConcept.cpp
@@ -260,6 +260,9 @@ calculateConstraintSatisfaction(Sema &S, const Expr *ConstraintExpr,
     return SubstitutedAtomicExpr;
   }
 
+  if (SubstitutedAtomicExpr.get()->isValueDependent())
+    return SubstitutedAtomicExpr;
+
   EnterExpressionEvaluationContext ConstantEvaluated(
       S, Sema::ExpressionEvaluationContext::ConstantEvaluated);
   SmallVector<PartialDiagnosticAt, 2> EvaluationDiags;
@@ -752,27 +755,43 @@ namespace {
   };
 } // namespace
 
+static const Expr *SubstituteConstraintExpression(Sema &S, const NamedDecl *ND,
+                                                  const Expr *ConstrExpr) {
+  MultiLevelTemplateArgumentList MLTAL = S.getTemplateInstantiationArgs(
+      ND, /*Final=*/false, /*Innermost=*/nullptr,
+      /*RelativeToPrimary=*/true,
+      /*Pattern=*/nullptr,
+      /*ForConstraintInstantiation=*/true, /*SkipForSpecialization*/ false);
+  if (MLTAL.getNumSubstitutedLevels() == 0)
+    return ConstrExpr;
+  Sema::SFINAETrap SFINAE(S, /*AccessCheckingSFINAE=*/false);
+  std::optional<Sema::CXXThisScopeRAII> ThisScope;
+  if (auto *RD = dyn_cast<CXXRecordDecl>(ND->getDeclContext()))
+    ThisScope.emplace(S, const_cast<CXXRecordDecl *>(RD), Qualifiers());
+  ExprResult SubstConstr =
+      S.SubstConstraintExpr(const_cast<clang::Expr *>(ConstrExpr), MLTAL);
+  if (SFINAE.hasErrorOccurred() || !SubstConstr.isUsable())
+    return nullptr;
+  return SubstConstr.get();
+}
+
 bool Sema::AreConstraintExpressionsEqual(const NamedDecl *Old,
                                          const Expr *OldConstr,
                                          const NamedDecl *New,
                                          const Expr *NewConstr) {
+  if (OldConstr == NewConstr)
+    return true;
   if (Old && New && Old != New) {
-    unsigned Depth1 = CalculateTemplateDepthForConstraints(
-        *this, Old);
-    unsigned Depth2 = CalculateTemplateDepthForConstraints(
-        *this, New);
-
-    // Adjust the 'shallowest' verison of this to increase the depth to match
-    // the 'other'.
-    if (Depth2 > Depth1) {
-      OldConstr = AdjustConstraintDepth(*this, Depth2 - Depth1)
-                      .TransformExpr(const_cast<Expr *>(OldConstr))
-                      .get();
-    } else if (Depth1 > Depth2) {
-      NewConstr = AdjustConstraintDepth(*this, Depth1 - Depth2)
-                      .TransformExpr(const_cast<Expr *>(NewConstr))
-                      .get();
-    }
+    if (const Expr *SubstConstr =
+            SubstituteConstraintExpression(*this, Old, OldConstr))
+      OldConstr = SubstConstr;
+    else
+      return false;
+    if (const Expr *SubstConstr =
+            SubstituteConstraintExpression(*this, New, NewConstr))
+      NewConstr = SubstConstr;
+    else
+      return false;
   }
 
   llvm::FoldingSetNodeID ID1, ID2;
diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp
index f10d937ed74d5..5cbd9e8a46234 100644
--- a/clang/lib/Sema/SemaOverload.cpp
+++ b/clang/lib/Sema/SemaOverload.cpp
@@ -1294,7 +1294,7 @@ bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old,
     // We check the return type and template parameter lists for function
     // templates first; the remaining checks follow.
     bool SameTemplateParameterList = TemplateParameterListsAreEqual(
-        NewTemplate->getTemplateParameters(),
+        NewTemplate, NewTemplate->getTemplateParameters(), OldTemplate,
         OldTemplate->getTemplateParameters(), false, TPL_TemplateMatch);
     bool SameReturnType = Context.hasSameType(Old->getDeclaredReturnType(),
                                               New->getDeclaredReturnType());
diff --git a/clang/lib/Sema/SemaTemplateInstantiate.cpp b/clang/lib/Sema/SemaTemplateInstantiate.cpp
index 162cf3cd88344..d88748761c148 100644
--- a/clang/lib/Sema/SemaTemplateInstantiate.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiate.cpp
@@ -208,6 +208,10 @@ Response HandleFunction(const FunctionDecl *Function,
   return Response::UseNextDecl(Function);
 }
 
+Response HandleFunctionTemplateDecl(const FunctionTemplateDecl *FTD) {
+  return Response::ChangeDecl(FTD->getLexicalDeclContext());
+}
+
 Response HandleRecordDecl(const CXXRecordDecl *Rec,
                           MultiLevelTemplateArgumentList &Result,
                           ASTContext &Context,
@@ -318,6 +322,8 @@ MultiLevelTemplateArgumentList Sema::getTemplateInstantiationArgs(
     } else if (const auto *CSD =
                    dyn_cast<ImplicitConceptSpecializationDecl>(CurDecl)) {
       R = HandleImplicitConceptSpecializationDecl(CSD, Result);
+    } else if (const auto *FTD = dyn_cast<FunctionTemplateDecl>(CurDecl)) {
+      R = HandleFunctionTemplateDecl(FTD);
     } else if (!isa<DeclContext>(CurDecl)) {
       R = Response::DontClearRelativeToPrimaryNextDecl(CurDecl);
       if (CurDecl->getDeclContext()->isTranslationUnit()) {
diff --git a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
index ce461b18978c4..ba64591c96498 100644
--- a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -1653,33 +1653,12 @@ Decl *TemplateDeclInstantiator::VisitClassTemplateDecl(ClassTemplateDecl *D) {
         << QualifierLoc.getSourceRange();
       return nullptr;
     }
-
-    if (PrevClassTemplate) {
-      const ClassTemplateDecl *MostRecentPrevCT =
-          PrevClassTemplate->getMostRecentDecl();
-      TemplateParameterList *PrevParams =
-          MostRecentPrevCT->getTemplateParameters();
-
-      // Make sure the parameter lists match.
-      if (!SemaRef.TemplateParameterListsAreEqual(
-              D->getTemplatedDecl(), InstParams,
-              MostRecentPrevCT->getTemplatedDecl(), PrevParams, true,
-              Sema::TPL_TemplateMatch))
-        return nullptr;
-
-      // Do some additional validation, then merge default arguments
-      // from the existing declarations.
-      if (SemaRef.CheckTemplateParameterList(InstParams, PrevParams,
-                                             Sema::TPC_ClassTemplate))
-        return nullptr;
-    }
   }
 
   CXXRecordDecl *RecordInst = CXXRecordDecl::Create(
       SemaRef.Context, Pattern->getTagKind(), DC, Pattern->getBeginLoc(),
       Pattern->getLocation(), Pattern->getIdentifier(), PrevDecl,
       /*DelayTypeCreation=*/true);
-
   if (QualifierLoc)
     RecordInst->setQualifierInfo(QualifierLoc);
 
@@ -1689,16 +1668,37 @@ Decl *TemplateDeclInstantiator::VisitClassTemplateDecl(ClassTemplateDecl *D) {
   ClassTemplateDecl *Inst
     = ClassTemplateDecl::Create(SemaRef.Context, DC, D->getLocation(),
                                 D->getIdentifier(), InstParams, RecordInst);
-  assert(!(isFriend && Owner->isDependentContext()));
-  Inst->setPreviousDecl(PrevClassTemplate);
-
   RecordInst->setDescribedClassTemplate(Inst);
 
   if (isFriend) {
-    if (PrevClassTemplate)
+    assert(!Owner->isDependentContext());
+    Inst->setLexicalDeclContext(Owner);
+    RecordInst->setLexicalDeclContext(Owner);
+
+    if (PrevClassTemplate) {
+      RecordInst->setTypeForDecl(
+          PrevClassTemplate->getTemplatedDecl()->getTypeForDecl());
+      const ClassTemplateDecl *MostRecentPrevCT =
+          PrevClassTemplate->getMostRecentDecl();
+      TemplateParameterList *PrevParams =
+          MostRecentPrevCT->getTemplateParameters();
+
+      // Make sure the parameter lists match.
+      if (!SemaRef.TemplateParameterListsAreEqual(
+              RecordInst, InstParams, MostRecentPrevCT->getTemplatedDecl(),
+              PrevParams, true, Sema::TPL_TemplateMatch))
+        return nullptr;
+
+      // Do some additional validation, then merge default arguments
+      // from the existing declarations.
+      if (SemaRef.CheckTemplateParameterList(InstParams, PrevParams,
+                                             Sema::TPC_ClassTemplate))
+        return nullptr;
+
       Inst->setAccess(PrevClassTemplate->getAccess());
-    else
+    } else {
       Inst->setAccess(D->getAccess());
+    }
 
     Inst->setObjectOfFriendDecl();
     // TODO: do we want to track the instantiation progeny of this
@@ -1709,15 +1709,15 @@ Decl *TemplateDeclInstantiator::VisitClassTemplateDecl(ClassTemplateDecl *D) {
       Inst->setInstantiatedFromMemberTemplate(D);
   }
 
+  Inst->setPreviousDecl(PrevClassTemplate);
+
   // Trigger creation of the type for the instantiation.
-  SemaRef.Context.getInjectedClassNameType(RecordInst,
-                                    Inst->getInjectedClassNameSpecialization());
+  SemaRef.Context.getInjectedClassNameType(
+      RecordInst, Inst->getInjectedClassNameSpecialization());
 
   // Finish handling of friends.
   if (isFriend) {
     DC->makeDeclVisibleInContext(Inst);
-    Inst->setLexicalDeclContext(Owner);
-    RecordInst->setLexicalDeclContext(Owner);
     return Inst;
   }
 
diff --git a/clang/test/SemaTemplate/concepts-out-of-line-def.cpp b/clang/test/SemaTemplate/concepts-out-of-line-def.cpp
index 222b78e0d22f7..a0fb1c3973035 100644
--- a/clang/test/SemaTemplate/concepts-out-of-line-def.cpp
+++ b/clang/test/SemaTemplate/concepts-out-of-line-def.cpp
@@ -127,3 +127,153 @@ static_assert(S<XY>::specialization("str") == SPECIALIZATION_CONCEPT);
 static_assert(S<int>::specialization("str") == SPECIALIZATION_REQUIRES);
 
 } // namespace multiple_template_parameter_lists
+
+static constexpr int CONSTRAINED_METHOD_1 = 1;
+static constexpr int CONSTRAINED_METHOD_2 = 2;
+
+namespace constrained_members {
+
+template <int>
+struct S {
+  template <Concept C>
+  static constexpr int constrained_method();
+};
+
+template <>
+template <Concept C>
+constexpr int S<1>::constrained_method() { return CONSTRAINED_METHOD_1; }
+
+template <>
+template <Concept C>
+constexpr int S<2>::constrained_method() { return CONSTRAINED_METHOD_2; }
+
+static_assert(S<1>::constrained_method<XY>() == CONSTRAINED_METHOD_1);
+static_assert(S<2>::constrained_method<XY>() == CONSTRAINED_METHOD_2);
+
+
+template <class T1, class T2>
+concept ConceptT1T2 = true;
+
+template<typename T3>
+struct S12 {
+  template<ConceptT1T2<T3> T4>
+  static constexpr int constrained_method();
+};
+
+template<>
+template<ConceptT1T2<int> T5>
+constexpr int S12<int>::constrained_method() { return CONSTRAINED_METHOD_1; }
+
+template<>
+template<ConceptT1T2<double> T5>
+constexpr int S12<double>::constrained_method() { return CONSTRAINED_METHOD_2; }
+
+static_assert(S12<int>::constrained_method<XY>() == CONSTRAINED_METHOD_1);
+static_assert(S12<double>::constrained_method<XY>() == CONSTRAINED_METHOD_2);
+
+} // namespace constrained members
+
+namespace constrained_members_of_nested_types {
+
+template <int>
+struct S {
+  struct Inner0 {
+    struct Inner1 {
+      template <Concept C>
+      static constexpr int constrained_method();
+    };
+  };
+};
+
+template <>
+template <Concept C>
+constexpr int S<1>::Inner0::Inner1::constrained_method() { return CONSTRAINED_METHOD_1; }
+
+template <>
+template <Concept C>
+constexpr int S<2>::Inner0::Inner1::constrained_method() { return CONSTRAINED_METHOD_2; }
+
+static_assert(S<1>::Inner0::Inner1::constrained_method<XY>() == CONSTRAINED_METHOD_1);
+static_assert(S<2>::Inner0::Inner1::constrained_method<XY>() == CONSTRAINED_METHOD_2);
+
+
+template <class T1, class T2>
+concept ConceptT1T2 = true;
+
+template<typename T3>
+struct S12 {
+  struct Inner0 {
+    struct Inner1 {
+      template<ConceptT1T2<T3> T4>
+      static constexpr int constrained_method();
+    };
+  };
+};
+
+template<>
+template<ConceptT1T2<int> T5>
+constexpr int S12<int>::Inner0::Inner1::constrained_method() { return CONSTRAINED_METHOD_1; }
+
+template<>
+template<ConceptT1T2<double> T5>
+constexpr int S12<double>::Inner0::Inner1::constrained_method() { return CONSTRAINED_METHOD_2; }
+
+static_assert(S12<int>::Inner0::Inner1::constrained_method<XY>() == CONSTRAINED_METHOD_1);
+static_assert(S12<double>::Inner0::Inner1::constrained_method<XY>() == CONSTRAINED_METHOD_2);
+
+} // namespace constrained_members_of_nested_types
+
+namespace constrained_member_sfinae {
+
+template<int N> struct S {
+  template<class T>
+  static constexpr int constrained_method() requires (sizeof(int[N * 1073741824 + 4]) == 16) {
+    return CONSTRAINED_METHOD_1;
+  }
+
+  template<class T>
+  static constexpr int constrained_method() requires (sizeof(int[N]) == 16);
+};
+
+template<>
+template<typename T>
+constexpr int S<4>::constrained_method() requires (sizeof(int[4]) == 16) {
+  return CONSTRAINED_METHOD_2;
+}
+
+// Verify that there is no amiguity in this case.
+static_assert(S<4>::constrained_method<double>() == CONSTRAINED_METHOD_2);
+
+} // namespace constrained_member_sfinae
+
+namespace requires_expression_references_members {
+
+void accept1(int x);
+void accept2(XY xy);
+
+template <class T> struct S {
+  T Field = T();
+
+  constexpr int constrained_method()
+      requires requires { accept1(Field); };
+
+  constexpr int constrained_method()
+      requires requires { accept2(Field); };
+};
+
+template <class T>
+constexpr int S<T>::constrained_method()
+  requires requires { accept1(Field); } {
+  return CONSTRAINED_METHOD_1;
+}
+
+template <class T>
+constexpr int S<T>::constrained_method()
+  requires requires { accept2(Field); } {
+  return CONSTRAINED_METHOD_2;
+}
+
+static_assert(S<int>().constrained_method() == CONSTRAINED_METHOD_1);
+static_assert(S<XY>().constrained_method() == CONSTRAINED_METHOD_2);
+
+} // namespace requires_expression_references_members
diff --git a/clang/test/SemaTemplate/concepts.cpp b/clang/test/SemaTemplate/concepts.cpp
index d28c2b22bd045..19638bba30724 100644
--- a/clang/test/SemaTemplate/concepts.cpp
+++ b/clang/test/SemaTemplate/concepts.cpp
@@ -816,3 +816,12 @@ static_assert(Parent<int>::TakesBinary<int, 0>::i == 0);
 static_assert(Parent<int>::TakesBinary<int, 0ULL>::i == 0);
 }
 
+namespace TemplateInsideNonTemplateClass {
+template<typename T, typename U> concept C = true;
+
+template<typename T> auto L = []<C<T> U>() {};
+
+struct Q {
+  template<C<int> U> friend constexpr auto decltype(L<int>)::operator()() const;
+};
+} // namespace TemplateInsideNonTemplateClass
diff --git a/clang/www/cxx_status.html b/clang/www/cxx_status.html
index fe2a16d9cee1f..601908b58a8f7 100755
--- a/clang/www/cxx_status.html
+++ b/clang/www/cxx_status.html
@@ -947,9 +947,6 @@ <h2 id="cxx20">C++20 implementation status</h2>
       <tr>
         <td><a href="https://wg21.link/p1980r0">P1980R0</a></td>
       </tr>
-      <tr> <!-- from Prague -->
-        <td><a href="https://wg21.link/p2103r0">P2103R0</a></td>
-      </tr>
       <tr> <!-- from February 2022 -->
         <td><a href="https://wg21.link/p2493r0">P2493R0</a></td>
       </tr>
@@ -961,6 +958,9 @@ <h2 id="cxx20">C++20 implementation status</h2>
         <td><a href="https://wg21.link/p2113r0">P2113R0</a></td>
         <td rowspan="1" class="full" align="center">Clang 16</td>
       </tr>
+      <tr>
+        <td><a href="https://wg21.link/p2103r0">P2103R0</a></td>
+      </tr>
     <!-- Albuquerque papers -->
     <tr>
       <td>Range-based for statements with initializer</td>