Bug 567261 - Revert "541239: [C++17] Implement parser support for deduction guides"

This reverts commit bcb955a32104da02f3748dd3ef080cbcb43c646b.

Change-Id: Iaf6ba398e439e3d1da1e3a3b0247c7b24bbfb057

19 files changed, 104 insertions, 760 deletions

diff --git a/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/DOMParserTestSuite.java b/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/DOMParserTestSuite.java
index f1fe6b37975..5f17ae73f30 100644
--- a/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/DOMParserTestSuite.java
+++ b/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/DOMParserTestSuite.java
@@ -20,7 +20,6 @@ import org.eclipse.cdt.core.parser.tests.ast2.cxx14.GenericLambdaTests;
 import org.eclipse.cdt.core.parser.tests.ast2.cxx14.InitCaptureTests;
 import org.eclipse.cdt.core.parser.tests.ast2.cxx14.ReturnTypeDeductionTests;
 import org.eclipse.cdt.core.parser.tests.ast2.cxx14.VariableTemplateTests;
-import org.eclipse.cdt.core.parser.tests.ast2.cxx17.DeductionGuideTests;
 import org.eclipse.cdt.core.parser.tests.ast2.cxx17.LambdaExpressionTests;
 import org.eclipse.cdt.core.parser.tests.ast2.cxx17.StructuredBindingTests;
 import org.eclipse.cdt.core.parser.tests.ast2.cxx17.TemplateAutoTests;
@@ -77,7 +76,6 @@ public class DOMParserTestSuite extends TestCase {
 		suite.addTest(TemplateAutoTests.suite());
 		suite.addTestSuite(LambdaExpressionTests.class);
 		suite.addTestSuite(StructuredBindingTests.class);
-		suite.addTestSuite(DeductionGuideTests.class);
 		return suite;
 	}
 }
diff --git a/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/cxx17/DeductionGuideTests.java b/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/cxx17/DeductionGuideTests.java
deleted file mode 100644
index 02705d96e5b..00000000000
--- a/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/cxx17/DeductionGuideTests.java
+++ /dev/null
@@ -1,187 +0,0 @@
-/*******************************************************************************
- * Copyright (c) 2018, Institute for Software and others.
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the Eclipse Public License v1.0
- * which accompanies this distribution, and is available at
- * http://www.eclipse.org/legal/epl-v10.html
- *
- * Contributors:
- *     Felix Morgner - initial API and implementation
- *******************************************************************************/
-
-package org.eclipse.cdt.core.parser.tests.ast2.cxx17;
-
-import static org.hamcrest.Matchers.arrayWithSize;
-import static org.hamcrest.Matchers.equalTo;
-import static org.hamcrest.Matchers.hasToString;
-import static org.hamcrest.Matchers.is;
-
-import org.eclipse.cdt.core.dom.ast.IASTDeclaration;
-import org.eclipse.cdt.core.dom.ast.IASTSimpleDeclaration;
-import org.eclipse.cdt.core.dom.ast.IASTTranslationUnit;
-import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTCompositeTypeSpecifier;
-import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTDeductionGuide;
-import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTTemplateDeclaration;
-import org.eclipse.cdt.core.parser.tests.ast2.AST2CPPTestBase;
-import org.eclipse.cdt.core.parser.util.ArrayUtil;
-import org.hamcrest.MatcherAssert;
-
-public class DeductionGuideTests extends AST2CPPTestBase {
-
-	private static ICPPASTDeductionGuide firstGuide(IASTDeclaration[] array) {
-		return (ICPPASTDeductionGuide) ArrayUtil.filter(array, d -> d instanceof ICPPASTDeductionGuide)[0];
-	}
-
-	// template<typename> struct U;
-	// U() -> U<int>;
-	public void testDeductionGuideWithoutArguments() throws Exception {
-		IASTDeclaration[] declarations = parseAndCheckBindings().getDeclarations();
-
-		ICPPASTDeductionGuide guide = firstGuide(declarations);
-		MatcherAssert.assertThat(guide.getParameters(), is(arrayWithSize(0)));
-		MatcherAssert.assertThat(guide.getTemplateName(), hasToString("U"));
-		MatcherAssert.assertThat(guide.getSimpleTemplateId().getTemplateName(), hasToString("U"));
-		MatcherAssert.assertThat(guide.isExplicit(), is(equalTo(false)));
-	}
-
-	// template<typename> struct U;
-	// U(int, float) -> U<int>;
-	public void testDeductionGuideWithArguments() throws Exception {
-		IASTDeclaration[] declarations = parseAndCheckBindings().getDeclarations();
-
-		ICPPASTDeductionGuide guide = firstGuide(declarations);
-		MatcherAssert.assertThat(guide.getParameters(), is(arrayWithSize(2)));
-		MatcherAssert.assertThat(guide.getTemplateName(), hasToString("U"));
-		MatcherAssert.assertThat(guide.getSimpleTemplateId().getTemplateName(), hasToString("U"));
-		MatcherAssert.assertThat(guide.isExplicit(), is(equalTo(false)));
-	}
-
-	// template<typename> struct U;
-	// template<typename T>
-	// U(T) -> U<T>;
-	public void testDeductionGuideTemplate() throws Exception {
-		IASTDeclaration[] declarations = parseAndCheckBindings().getDeclarations();
-		ICPPASTTemplateDeclaration template = (ICPPASTTemplateDeclaration) declarations[1];
-		ICPPASTDeductionGuide guide = (ICPPASTDeductionGuide) template.getDeclaration();
-
-		MatcherAssert.assertThat(guide.getParameters(), is(arrayWithSize(1)));
-		MatcherAssert.assertThat(guide.getTemplateName(), hasToString("U"));
-		MatcherAssert.assertThat(guide.getSimpleTemplateId().getTemplateName(), hasToString("U"));
-		MatcherAssert.assertThat(guide.isExplicit(), is(equalTo(false)));
-	}
-
-	// template<typename> struct U;
-	// explicit U() -> U<int>;
-	public void testExplicitDeductionGuide() throws Exception {
-		IASTDeclaration[] declarations = parseAndCheckBindings().getDeclarations();
-
-		ICPPASTDeductionGuide guide = firstGuide(declarations);
-		MatcherAssert.assertThat(guide.getParameters(), is(arrayWithSize(0)));
-		MatcherAssert.assertThat(guide.getTemplateName(), hasToString("U"));
-		MatcherAssert.assertThat(guide.getSimpleTemplateId().getTemplateName(), hasToString("U"));
-		MatcherAssert.assertThat(guide.isExplicit(), is(equalTo(true)));
-	}
-
-	// template<typename> struct U;
-	// template<typename T>
-	// explicit U(T) -> U<T>;
-	public void testExplicitDeductionGuideTemplate() throws Exception {
-		IASTDeclaration[] declarations = parseAndCheckBindings().getDeclarations();
-		ICPPASTTemplateDeclaration template = (ICPPASTTemplateDeclaration) declarations[1];
-		ICPPASTDeductionGuide guide = (ICPPASTDeductionGuide) template.getDeclaration();
-
-		MatcherAssert.assertThat(guide.getParameters(), is(arrayWithSize(1)));
-		MatcherAssert.assertThat(guide.getTemplateName(), hasToString("U"));
-		MatcherAssert.assertThat(guide.getSimpleTemplateId().getTemplateName(), hasToString("U"));
-		MatcherAssert.assertThat(guide.isExplicit(), is(equalTo(true)));
-	}
-
-	// struct S {
-	// 	template<typename> struct U;
-	// 	U() -> U<int>;
-	// };
-	public void testDeductionGuideWithoutArgumentsForNestedClassType() throws Exception {
-		IASTTranslationUnit tu = parseAndCheckBindings();
-		IASTSimpleDeclaration declaration = (IASTSimpleDeclaration) tu.getDeclarations()[0];
-		ICPPASTCompositeTypeSpecifier struct = (ICPPASTCompositeTypeSpecifier) declaration.getDeclSpecifier();
-		IASTDeclaration[] members = struct.getMembers();
-
-		ICPPASTDeductionGuide guide = firstGuide(members);
-		MatcherAssert.assertThat(guide.getParameters(), is(arrayWithSize(0)));
-		MatcherAssert.assertThat(guide.getTemplateName(), hasToString("U"));
-		MatcherAssert.assertThat(guide.getSimpleTemplateId().getTemplateName(), hasToString("U"));
-		MatcherAssert.assertThat(guide.isExplicit(), is(equalTo(false)));
-	}
-
-	// struct S {
-	// 	template<typename> struct U;
-	// 	U(char, bool) -> U<double>;
-	// };
-	public void testDeductionGuideWithArgumentsForNestedClassType() throws Exception {
-		IASTTranslationUnit tu = parseAndCheckBindings();
-		IASTSimpleDeclaration declaration = (IASTSimpleDeclaration) tu.getDeclarations()[0];
-		ICPPASTCompositeTypeSpecifier struct = (ICPPASTCompositeTypeSpecifier) declaration.getDeclSpecifier();
-		IASTDeclaration[] members = struct.getMembers();
-
-		ICPPASTDeductionGuide guide = firstGuide(members);
-		MatcherAssert.assertThat(guide.getParameters(), is(arrayWithSize(2)));
-		MatcherAssert.assertThat(guide.getTemplateName(), hasToString("U"));
-		MatcherAssert.assertThat(guide.getSimpleTemplateId().getTemplateName(), hasToString("U"));
-		MatcherAssert.assertThat(guide.isExplicit(), is(equalTo(false)));
-	}
-
-	// struct S {
-	// 	template<typename> struct U;
-	// 	template<typename T>
-	// 	U(T) -> U<T>;
-	// };
-	public void testDeductionGuideTemplateWithArgumentsForNestedClassType() throws Exception {
-		IASTTranslationUnit tu = parseAndCheckBindings();
-		IASTSimpleDeclaration declaration = (IASTSimpleDeclaration) tu.getDeclarations()[0];
-		ICPPASTCompositeTypeSpecifier struct = (ICPPASTCompositeTypeSpecifier) declaration.getDeclSpecifier();
-		IASTDeclaration[] members = struct.getMembers();
-		ICPPASTTemplateDeclaration template = (ICPPASTTemplateDeclaration) members[1];
-
-		ICPPASTDeductionGuide guide = (ICPPASTDeductionGuide) template.getDeclaration();
-		MatcherAssert.assertThat(guide.getParameters(), is(arrayWithSize(1)));
-		MatcherAssert.assertThat(guide.getTemplateName(), hasToString("U"));
-		MatcherAssert.assertThat(guide.getSimpleTemplateId().getTemplateName(), hasToString("U"));
-		MatcherAssert.assertThat(guide.isExplicit(), is(equalTo(false)));
-	}
-
-	// struct S {
-	// 	template<typename> struct U;
-	// 	explicit U() -> U<int>;
-	// };
-	public void testExplicitDeductionGuideForNestedClassType() throws Exception {
-		IASTTranslationUnit tu = parseAndCheckBindings();
-		IASTSimpleDeclaration declaration = (IASTSimpleDeclaration) tu.getDeclarations()[0];
-		ICPPASTCompositeTypeSpecifier struct = (ICPPASTCompositeTypeSpecifier) declaration.getDeclSpecifier();
-		IASTDeclaration[] members = struct.getMembers();
-
-		ICPPASTDeductionGuide guide = firstGuide(members);
-		MatcherAssert.assertThat(guide.getParameters(), is(arrayWithSize(0)));
-		MatcherAssert.assertThat(guide.getTemplateName(), hasToString("U"));
-		MatcherAssert.assertThat(guide.getSimpleTemplateId().getTemplateName(), hasToString("U"));
-		MatcherAssert.assertThat(guide.isExplicit(), is(equalTo(true)));
-	}
-
-	// struct S {
-	// 	template<typename> struct U;
-	// 	template<typename T>
-	// 	explicit U(T) -> U<T>;
-	// };
-	public void testExplicitDeductionGuideTemplateForNestedClassType() throws Exception {
-		IASTTranslationUnit tu = parseAndCheckBindings();
-		IASTSimpleDeclaration declaration = (IASTSimpleDeclaration) tu.getDeclarations()[0];
-		ICPPASTCompositeTypeSpecifier struct = (ICPPASTCompositeTypeSpecifier) declaration.getDeclSpecifier();
-		IASTDeclaration[] members = struct.getMembers();
-		ICPPASTTemplateDeclaration template = (ICPPASTTemplateDeclaration) members[1];
-
-		ICPPASTDeductionGuide guide = (ICPPASTDeductionGuide) template.getDeclaration();
-		MatcherAssert.assertThat(guide.getParameters(), is(arrayWithSize(1)));
-		MatcherAssert.assertThat(guide.getTemplateName(), hasToString("U"));
-		MatcherAssert.assertThat(guide.getSimpleTemplateId().getTemplateName(), hasToString("U"));
-		MatcherAssert.assertThat(guide.isExplicit(), is(equalTo(true)));
-	}
-}
diff --git a/core/org.eclipse.cdt.core/.settings/.api_filters b/core/org.eclipse.cdt.core/.settings/.api_filters
new file mode 100644
index 00000000000..6cce4ae2d23
--- /dev/null
+++ b/core/org.eclipse.cdt.core/.settings/.api_filters
@@ -0,0 +1,63 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<component id="org.eclipse.cdt.core" version="2">
+    <resource path="META-INF/MANIFEST.MF" type="org.eclipse.cdt.core.dom.ast.cpp.ICPPASTDeductionGuide">
+        <filter comment="deduction guides have been reverted post release" id="305324134">
+            <message_arguments>
+                <message_argument value="org.eclipse.cdt.core.dom.ast.cpp.ICPPASTDeductionGuide"/>
+                <message_argument value="org.eclipse.cdt.core_7.1.0"/>
+            </message_arguments>
+        </filter>
+    </resource>
+    <resource path="META-INF/MANIFEST.MF" type="org.eclipse.cdt.core.dom.ast.cpp.ICPPASTParameterListOwner">
+        <filter comment="deduction guides have been reverted post release" id="305324134">
+            <message_arguments>
+                <message_argument value="org.eclipse.cdt.core.dom.ast.cpp.ICPPASTParameterListOwner"/>
+                <message_argument value="org.eclipse.cdt.core_7.1.0"/>
+            </message_arguments>
+        </filter>
+    </resource>
+    <resource path="parser/org/eclipse/cdt/core/dom/ast/cpp/ICPPASTFunctionDeclarator.java" type="org.eclipse.cdt.core.dom.ast.cpp.ICPPASTFunctionDeclarator">
+        <filter comment="asdf" id="404791350">
+            <message_arguments>
+                <message_argument value="org.eclipse.cdt.core.dom.ast.cpp.ICPPASTFunctionDeclarator"/>
+                <message_argument value="org.eclipse.cdt.core.dom.ast.cpp.ICPPASTParameterListOwner"/>
+            </message_arguments>
+        </filter>
+    </resource>
+    <resource path="parser/org/eclipse/cdt/core/dom/ast/cpp/ICPPASTFunctionTryBlockDeclarator.java" type="org.eclipse.cdt.core.dom.ast.cpp.ICPPASTFunctionTryBlockDeclarator">
+        <filter comment="asdf" id="404791350">
+            <message_arguments>
+                <message_argument value="org.eclipse.cdt.core.dom.ast.cpp.ICPPASTFunctionTryBlockDeclarator"/>
+                <message_argument value="org.eclipse.cdt.core.dom.ast.cpp.ICPPASTParameterListOwner"/>
+            </message_arguments>
+        </filter>
+    </resource>
+    <resource path="src/org/eclipse/cdt/core/formatter/DefaultCodeFormatterConstants.java" type="org.eclipse.cdt.core.formatter.DefaultCodeFormatterConstants">
+        <filter comment="asdf" id="338755678">
+            <message_arguments>
+                <message_argument value="org.eclipse.cdt.core.formatter.DefaultCodeFormatterConstants"/>
+                <message_argument value="FORMATTER_INSERT_SPACE_AFTER_DEDUCTION_GUIDE_ARROW"/>
+            </message_arguments>
+        </filter>
+        <filter comment="asdf" id="338755678">
+            <message_arguments>
+                <message_argument value="org.eclipse.cdt.core.formatter.DefaultCodeFormatterConstants"/>
+                <message_argument value="FORMATTER_INSERT_SPACE_BEFORE_DEDUCTION_GUIDE_ARROW"/>
+            </message_arguments>
+        </filter>
+    </resource>
+    <resource path="src/org/eclipse/cdt/core/formatter/DefaultCodeFormatterOptions.java" type="org.eclipse.cdt.core.formatter.DefaultCodeFormatterOptions">
+        <filter comment="asdf" id="338755678">
+            <message_arguments>
+                <message_argument value="org.eclipse.cdt.core.formatter.DefaultCodeFormatterOptions"/>
+                <message_argument value="insert_space_after_deduction_guide_arrow"/>
+            </message_arguments>
+        </filter>
+        <filter comment="asdf" id="338755678">
+            <message_arguments>
+                <message_argument value="org.eclipse.cdt.core.formatter.DefaultCodeFormatterOptions"/>
+                <message_argument value="insert_space_before_deduction_guide_arrow"/>
+            </message_arguments>
+        </filter>
+    </resource>
+</component>
diff --git a/core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/model/CModelBuilder2.java b/core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/model/CModelBuilder2.java
index 4364123abb1..63c983b1b11 100644
--- a/core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/model/CModelBuilder2.java
+++ b/core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/model/CModelBuilder2.java
@@ -55,7 +55,6 @@ import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTAliasDeclaration;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTCompositeTypeSpecifier;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTCompositeTypeSpecifier.ICPPASTBaseSpecifier;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTDeclSpecifier;
-import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTDeductionGuide;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTElaboratedTypeSpecifier;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTExplicitTemplateInstantiation;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTFunctionDeclarator;
@@ -353,8 +352,6 @@ public class CModelBuilder2 implements IContributedModelBuilder {
 			// TODO [cmodel] problem declaration?
 		} else if (declaration instanceof ICPPASTStaticAssertDeclaration) {
 			// ignore
-		} else if (declaration instanceof ICPPASTDeductionGuide) {
-			// TODO [cmodel] deduction guide?
 		} else {
 			assert false : "TODO: " + declaration.getClass().getName(); //$NON-NLS-1$
 		}
@@ -419,8 +416,6 @@ public class CModelBuilder2 implements IContributedModelBuilder {
 			createTemplateDeclaration(parent, (ICPPASTTemplateDeclaration) declaration);
 		} else if (declaration instanceof IASTProblemDeclaration) {
 			// ignore problem declarations (or create special elements for debugging?)
-		} else if (declaration instanceof ICPPASTDeductionGuide) {
-			// TODO [cmodel] deduction guide?
 		} else {
 			assert false : "TODO: " + declaration.getClass().getName(); //$NON-NLS-1$
 		}
diff --git a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/core/dom/ast/cpp/ICPPASTDeductionGuide.java b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/core/dom/ast/cpp/ICPPASTDeductionGuide.java
deleted file mode 100644
index 5aa81170753..00000000000
--- a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/core/dom/ast/cpp/ICPPASTDeductionGuide.java
+++ /dev/null
@@ -1,99 +0,0 @@
-/*******************************************************************************
- * Copyright (c) 2018, Institute for Software and others.
- *
- * This program and the accompanying materials
- * are made available under the terms of the Eclipse Public License 2.0
- * which accompanies this distribution, and is available at
- * https://www.eclipse.org/legal/epl-2.0/
- *
- * SPDX-License-Identifier: EPL-2.0
- *
- * Contributors:
- *     Felix Morgner - initial API and implementation
- *******************************************************************************/
-package org.eclipse.cdt.core.dom.ast.cpp;
-
-import org.eclipse.cdt.core.dom.ast.ASTNodeProperty;
-import org.eclipse.cdt.core.dom.ast.IASTDeclaration;
-import org.eclipse.cdt.core.dom.ast.IASTName;
-
-/**
- * A C++ class-template argument deduction guide
- * <p>
- * e.g:
- *
- * <pre>
- * SomeTemplateName(int) -> SomeTemplateName&lt;float&gt;;
- *
- * template&lt;typename I&gt;
- * SomeTemplateName(I, I) -> SomeTemplateName&lt;typename std::iterator_traits&lt;I&gt;::value_type&gt;;
- * </pre>
- * </p>
- *
- * @noimplement This interface is not intended to be implemented by clients.
- * @noextend This interface is not intended to be extended by clients.
- * @since 7.0
- */
-public interface ICPPASTDeductionGuide extends IASTDeclaration, ICPPASTParameterListOwner {
-
-	/**
-	 * <code>TEMPLATE_NAME</code> represents the relationship between an
-	 * <code>ICPPASTDeductionGuide</code> and it's nested
-	 * <code>IASTName</code>.
-	 */
-	static final ASTNodeProperty TEMPLATE_NAME = new ASTNodeProperty(
-			"ICPPASTDeductionGuide.TEMPLATE_NAME - IASTName for ICPPASTDeductionGuide"); //$NON-NLS-1$
-
-	/**
-	 * <code>TEMPLATE_ID</code> represents the relationship between an
-	 * <code>ICPPASTDeductionGuide</code> and it's nested
-	 * <code>ICPPASTTemplateId</code>.
-	 */
-	static final ASTNodeProperty TEMPLATE_ID = new ASTNodeProperty(
-			"ICPPASTDeductionGuide.TEMPLATE_ID - ICPPASTTemplateId for ICPPASTDeductionGuide"); //$NON-NLS-1$
-
-	/**
-	 * <code>PARAMETER</code> represents the relationship between an
-	 * <code>ICPPASTDeductionGuide</code> and it's nested
-	 * <code>IASTParameterDeclaration</code>.
-	 */
-	public final static ASTNodeProperty PARAMETER = new ASTNodeProperty(
-			"ICPPASTDeductionGuide.PARAMETER - IASTParameterDeclaration for ICPPASTDeductionGuide"); //$NON-NLS-1$
-
-	/**
-	 * Check if the deduction guide was declared as 'explicit'.
-	 */
-	boolean isExplicit();
-
-	/**
-	 * Set whether or not the deduction guide is marked explicit
-	 */
-	void setExplicit(boolean isExplict);
-
-	/**
-	 * Get the name of the template type the deduction guide refers to
-	 */
-	IASTName getTemplateName();
-
-	/**
-	 * Set the name of the template type the deduction guide refers to
-	 */
-	void setTemplateName(IASTName name);
-
-	/**
-	 * Get the template id of the deduction guide
-	 */
-	ICPPASTTemplateId getSimpleTemplateId();
-
-	/**
-	 * Set the template id of the deduction guide
-	 */
-	void setSimpleTemplateId(ICPPASTTemplateId id);
-
-	@Override
-	public ICPPASTDeductionGuide copy();
-
-	@Override
-	public ICPPASTDeductionGuide copy(CopyStyle style);
-
-}
diff --git a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/core/dom/ast/cpp/ICPPASTFunctionDeclarator.java b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/core/dom/ast/cpp/ICPPASTFunctionDeclarator.java
index 6439663bb7b..0180b30de3c 100644
--- a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/core/dom/ast/cpp/ICPPASTFunctionDeclarator.java
+++ b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/core/dom/ast/cpp/ICPPASTFunctionDeclarator.java
@@ -29,8 +29,7 @@ import org.eclipse.cdt.internal.core.dom.parser.cpp.ICPPEvaluation;
  * @noimplement This interface is not intended to be implemented by clients.
  * @noextend This interface is not intended to be extended by clients.
  */
-public interface ICPPASTFunctionDeclarator
-		extends IASTStandardFunctionDeclarator, ICPPASTDeclarator, ICPPASTParameterListOwner {
+public interface ICPPASTFunctionDeclarator extends IASTStandardFunctionDeclarator, ICPPASTDeclarator {
 	/**
 	 * @since 5.9
 	 */
diff --git a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/core/dom/ast/cpp/ICPPASTParameterListOwner.java b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/core/dom/ast/cpp/ICPPASTParameterListOwner.java
deleted file mode 100644
index a5106773295..00000000000
--- a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/core/dom/ast/cpp/ICPPASTParameterListOwner.java
+++ /dev/null
@@ -1,42 +0,0 @@
-/*******************************************************************************
- * Copyright (c) 2018, Institute for Software and others.
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the Eclipse Public License v1.0
- * which accompanies this distribution, and is available at
- * http://www.eclipse.org/legal/epl-v10.html
- *
- * Contributors:
- *     Felix Morgner - initial API and implementation
- *******************************************************************************/
-
-package org.eclipse.cdt.core.dom.ast.cpp;
-
-import org.eclipse.cdt.core.dom.ast.IASTParameterDeclaration;
-
-/**
- * Internal interface to describe the ability of having a parameter list
- * @since 7.0
- */
-public interface ICPPASTParameterListOwner {
-
-	/**
-	 * Add a parameter to the parameter list of the parameter list owner.
-	 */
-	public void addParameterDeclaration(IASTParameterDeclaration parameter);
-
-	/**
-	 * Gets the parameter declarations for the parameter list owner
-	 */
-	public IASTParameterDeclaration[] getParameters();
-
-	/**
-	 * Set whether or not the parameter list owner takes a variable number of
-	 * arguments.
-	 */
-	public void setVarArgs(boolean value);
-
-	/**
-	 * Check if the parameter list owner takes a variable number of arguments.
-	 */
-	public boolean takesVarArgs();
-}
diff --git a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/DeclarationOptions.java b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/DeclarationOptions.java
index 50376275f05..1c8285c104b 100644
--- a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/DeclarationOptions.java
+++ b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/DeclarationOptions.java
@@ -34,15 +34,14 @@ public class DeclarationOptions {
 	final public static int SINGLE_DTOR = 0x4000;
 	final public static int ALLOW_FUNCTION_DEFINITION = 0x8000;
 	final public static int NO_COMPOSITE_SPECIFIER = 0x10000;
-	final public static int ALLOW_DEDUCTION_GUIDE = 0x20000;
 
 	public static final DeclarationOptions GLOBAL = new DeclarationOptions(
-			ALLOW_EMPTY_SPECIFIER | ALLOW_OPAQUE_ENUM | ALLOW_FUNCTION_DEFINITION | ALLOW_DEDUCTION_GUIDE),
+			ALLOW_EMPTY_SPECIFIER | ALLOW_OPAQUE_ENUM | ALLOW_FUNCTION_DEFINITION),
 			FUNCTION_STYLE_ASM = new DeclarationOptions(
 					ALLOW_EMPTY_SPECIFIER | NO_INITIALIZER | ALLOW_ABSTRACT | ALLOW_FUNCTION_DEFINITION),
 			C_MEMBER = new DeclarationOptions(ALLOW_BITFIELD | ALLOW_ABSTRACT),
 			CPP_MEMBER = new DeclarationOptions(ALLOW_EMPTY_SPECIFIER | ALLOW_BITFIELD | ALLOW_OPAQUE_ENUM
-					| NO_CTOR_STYLE_INITIALIZER | ALLOW_FUNCTION_DEFINITION | ALLOW_DEDUCTION_GUIDE),
+					| NO_CTOR_STYLE_INITIALIZER | ALLOW_FUNCTION_DEFINITION),
 			LOCAL = new DeclarationOptions(ALLOW_OPAQUE_ENUM),
 			PARAMETER = new DeclarationOptions(ALLOW_ABSTRACT | ALLOW_PARAMETER_PACKS | REQUIRE_SIMPLE_NAME
 					| NO_BRACED_INITIALIZER | NO_CTOR_STYLE_INITIALIZER),
diff --git a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/CPPASTAmbiguousTemplateArgument.java b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/CPPASTAmbiguousTemplateArgument.java
index 5fc12dbdfd0..29590cb6bcc 100644
--- a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/CPPASTAmbiguousTemplateArgument.java
+++ b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/CPPASTAmbiguousTemplateArgument.java
@@ -47,7 +47,6 @@ public class CPPASTAmbiguousTemplateArgument extends ASTAmbiguousNode implements
 		fNodes = new ArrayList<>(2);
 		for (IASTNode node : nodes) {
 			if (node instanceof IASTTypeId || node instanceof IASTExpression) {
-				node.setParent(this);
 				fNodes.add(node);
 			} else {
 				Assert.isLegal(false, node == null ? "null" : node.getClass().getName()); //$NON-NLS-1$
diff --git a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/CPPASTDeductionGuide.java b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/CPPASTDeductionGuide.java
deleted file mode 100644
index edcfcddb3f4..00000000000
--- a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/CPPASTDeductionGuide.java
+++ /dev/null
@@ -1,174 +0,0 @@
-/*******************************************************************************
- * Copyright (c) 2018, Institute for Software and others.
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the Eclipse Public License v1.0
- * which accompanies this distribution, and is available at
- * http://www.eclipse.org/legal/epl-v10.html
- *
- * Contributors:
- *     Felix Morgner - initial API and implementation
- *******************************************************************************/
-
-package org.eclipse.cdt.internal.core.dom.parser.cpp;
-
-import org.eclipse.cdt.core.dom.ast.ASTVisitor;
-import org.eclipse.cdt.core.dom.ast.IASTName;
-import org.eclipse.cdt.core.dom.ast.IASTNode;
-import org.eclipse.cdt.core.dom.ast.IASTParameterDeclaration;
-import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTDeductionGuide;
-import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTParameterDeclaration;
-import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTTemplateId;
-import org.eclipse.cdt.core.parser.util.ArrayUtil;
-import org.eclipse.cdt.internal.core.dom.parser.ASTNode;
-import org.eclipse.cdt.internal.core.dom.parser.IASTAmbiguityParent;
-
-public class CPPASTDeductionGuide extends ASTNode implements ICPPASTDeductionGuide, IASTAmbiguityParent {
-
-	private IASTParameterDeclaration[] parameters;
-	private IASTName templateName;
-	private ICPPASTTemplateId templateId;
-	private boolean takesVarArgs;
-	private boolean isExplicit;
-
-	@Override
-	public boolean accept(ASTVisitor visitor) {
-		if (visitor.shouldVisitDeclarations) {
-			switch (visitor.visit(this)) {
-			case ASTVisitor.PROCESS_ABORT:
-				return false;
-			case ASTVisitor.PROCESS_SKIP:
-				return true;
-			default:
-				break;
-			}
-		}
-
-		if (!templateName.accept(visitor)) {
-			return false;
-		}
-
-		if (parameters != null) {
-			for (IASTParameterDeclaration parameter : parameters) {
-				if (parameter != null && !parameter.accept(visitor)) {
-					return false;
-				}
-			}
-		}
-
-		if (!templateId.accept(visitor)) {
-			return false;
-		}
-
-		if (visitor.shouldVisitDeclarations) {
-			switch (visitor.leave(this)) {
-			case ASTVisitor.PROCESS_ABORT:
-				return false;
-			case ASTVisitor.PROCESS_SKIP:
-				return true;
-			default:
-				break;
-			}
-		}
-		return true;
-	}
-
-	@Override
-	public void addParameterDeclaration(IASTParameterDeclaration parameter) {
-		assertNotFrozen();
-		assert (parameter != null);
-		parameter.setParent(this);
-		parameter.setPropertyInParent(PARAMETER);
-		parameters = ArrayUtil.append(IASTParameterDeclaration.class, parameters, parameter);
-	}
-
-	@Override
-	public IASTParameterDeclaration[] getParameters() {
-		if (parameters == null) {
-			return ICPPASTParameterDeclaration.EMPTY_CPPPARAMETERDECLARATION_ARRAY;
-		}
-		return ArrayUtil.trim(parameters);
-	}
-
-	@Override
-	public void setVarArgs(boolean value) {
-		assertNotFrozen();
-		takesVarArgs = value;
-	}
-
-	@Override
-	public boolean takesVarArgs() {
-		return takesVarArgs;
-	}
-
-	@Override
-	public boolean isExplicit() {
-		return isExplicit;
-	}
-
-	@Override
-	public void setExplicit(boolean value) {
-		assertNotFrozen();
-		isExplicit = value;
-	}
-
-	@Override
-	public IASTName getTemplateName() {
-		return templateName;
-	}
-
-	@Override
-	public void setTemplateName(IASTName name) {
-		assertNotFrozen();
-		assert (name != null);
-		name.setParent(this);
-		name.setPropertyInParent(TEMPLATE_NAME);
-		templateName = name;
-	}
-
-	@Override
-	public ICPPASTTemplateId getSimpleTemplateId() {
-		return templateId;
-	}
-
-	@Override
-	public void setSimpleTemplateId(ICPPASTTemplateId id) {
-		assertNotFrozen();
-		assert (id != null);
-		id.setParent(this);
-		id.setPropertyInParent(TEMPLATE_ID);
-		templateId = id;
-	}
-
-	@Override
-	public ICPPASTDeductionGuide copy() {
-		return copy(CopyStyle.withoutLocations);
-	}
-
-	@Override
-	public ICPPASTDeductionGuide copy(CopyStyle style) {
-		CPPASTDeductionGuide copy = new CPPASTDeductionGuide();
-		copy.isExplicit = isExplicit;
-		copy.takesVarArgs = takesVarArgs;
-		copy.setTemplateName(templateName.copy(style));
-		copy.setSimpleTemplateId(templateId.copy(style));
-		if (parameters != null) {
-			for (IASTParameterDeclaration parameter : parameters) {
-				if (parameter != null) {
-					copy.addParameterDeclaration(parameter.copy(style));
-				}
-			}
-		}
-		return super.copy(copy, style);
-	}
-
-	@Override
-	public void replace(IASTNode child, IASTNode other) {
-		int indexOfChild = ArrayUtil.indexOfEqual(parameters, child);
-		if (indexOfChild > -1) {
-			other.setParent(this);
-			other.setPropertyInParent(PARAMETER);
-			child.setParent(null);
-			parameters[indexOfChild] = (IASTParameterDeclaration) other;
-		}
-	}
-}
diff --git a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/GNUCPPSourceParser.java b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/GNUCPPSourceParser.java
index 227f8699cb2..85c3b2de9eb 100644
--- a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/GNUCPPSourceParser.java
+++ b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/GNUCPPSourceParser.java
@@ -127,7 +127,6 @@ import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTNewExpression;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTOperatorName;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTPackExpandable;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTParameterDeclaration;
-import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTParameterListOwner;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTQualifiedName;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTRangeBasedForStatement;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTReferenceOperator;
@@ -3056,35 +3055,6 @@ public class GNUCPPSourceParser extends AbstractGNUSourceCodeParser {
 			throwBacktrack(LA(1));
 		}
 
-		if (dtor instanceof ICPPASTFunctionDeclarator
-				&& ((ICPPASTFunctionDeclarator) dtor).getTrailingReturnType() != null) {
-			if (declSpec instanceof IASTSimpleDeclSpecifier
-					&& ((IASTSimpleDeclSpecifier) declSpec).getType() == IASTSimpleDeclSpecifier.t_unspecified) {
-				// we encountered something that looks like a ctor with trailing return type
-				CPPASTDeductionGuide guide = new CPPASTDeductionGuide();
-				guide.setExplicit(((ICPPASTDeclSpecifier) declSpec).isExplicit());
-				guide.setTemplateName(dtor.getName());
-				ICPPASTParameterDeclaration[] params = ((ICPPASTFunctionDeclarator) dtor).getParameters();
-				for (ICPPASTParameterDeclaration p : params)
-					guide.addParameterDeclaration(p);
-				guide.setVarArgs(((ICPPASTFunctionDeclarator) dtor).takesVarArgs());
-				IASTTypeId nameSpecifier = ((ICPPASTFunctionDeclarator) dtor).getTrailingReturnType();
-				IASTDeclSpecifier guideDeclSpec = nameSpecifier.getDeclSpecifier();
-				if (guideDeclSpec instanceof ICPPASTNamedTypeSpecifier) {
-					IASTName n = ((ICPPASTNamedTypeSpecifier) guideDeclSpec).getName();
-					if (n instanceof ICPPASTTemplateId) {
-						guide.setSimpleTemplateId((ICPPASTTemplateId) n);
-					} else {
-						throwBacktrack(dtor);
-					}
-				} else {
-					throwBacktrack(dtor);
-				}
-				setRange(guide, firstOffset, endOffset);
-				return guide;
-			}
-		}
-
 		// no function body
 
 		final boolean isAmbiguous = altDeclSpec != null && altDtor != null && declarators.length == 1;
@@ -4013,20 +3983,6 @@ public class GNUCPPSourceParser extends AbstractGNUSourceCodeParser {
 				}
 			}
 
-			//Check if it's a possible C++17 deduction guide
-			if (dtor instanceof ICPPASTFunctionDeclarator) {
-				ICPPASTFunctionDeclarator possibleGuide = (ICPPASTFunctionDeclarator) dtor;
-				IASTTypeId returnType = possibleGuide.getTrailingReturnType();
-				if (returnType != null) {
-					IASTDeclSpecifier declSpec = returnType.getDeclSpecifier();
-					if (declSpec instanceof ICPPASTNamedTypeSpecifier) {
-						IASTName n = ((ICPPASTNamedTypeSpecifier) declSpec).getName();
-						if (n instanceof ICPPASTTemplateId)
-							return;
-					}
-				}
-			}
-
 			ASTNode node = (ASTNode) dtor;
 			throwBacktrack(node.getOffset(), node.getLength());
 		}
@@ -4799,7 +4755,44 @@ public class GNUCPPSourceParser extends AbstractGNUSourceCodeParser {
 		int endOffset = last.getEndOffset();
 
 		final ICPPASTFunctionDeclarator fc = getNodeFactory().newFunctionDeclarator(null);
-		endOffset = parameterList(startOffset, endOffset, fc);
+		ICPPASTParameterDeclaration pd = null;
+		paramLoop: while (true) {
+			switch (LT(1)) {
+			case IToken.tRPAREN:
+			case IToken.tEOC:
+				endOffset = consume().getEndOffset();
+				break paramLoop;
+			case IToken.tELLIPSIS:
+				consume();
+				endOffset = consume(IToken.tRPAREN).getEndOffset();
+				fc.setVarArgs(true);
+				break paramLoop;
+			case IToken.tCOMMA:
+				if (pd == null)
+					throwBacktrack(LA(1));
+				endOffset = consume().getEndOffset();
+				pd = null;
+				break;
+			default:
+				if (pd != null)
+					throwBacktrack(startOffset, endOffset - startOffset);
+
+				pd = parameterDeclaration();
+				fc.addParameterDeclaration(pd);
+				endOffset = calculateEndOffset(pd);
+				break;
+			}
+		}
+		// Handle ambiguity between parameter pack and varargs.
+		if (pd != null) {
+			ICPPASTDeclarator dtor = pd.getDeclarator();
+			if (dtor != null && !(dtor instanceof IASTAmbiguousDeclarator)) {
+				if (dtor.declaresParameterPack() && dtor.getNestedDeclarator() == null && dtor.getInitializer() == null
+						&& dtor.getName().getSimpleID().length == 0) {
+					((IASTAmbiguityParent) fc).replace(pd, new CPPASTAmbiguousParameterDeclaration(pd));
+				}
+			}
+		}
 
 		// Consume any number of __attribute__ tokens after the parameters
 		List<IASTAttributeSpecifier> attributes = __attribute_decl_seq(supportAttributeSpecifiers, false);
@@ -4915,58 +4908,6 @@ public class GNUCPPSourceParser extends AbstractGNUSourceCodeParser {
 	}
 
 	/**
-	 * Parse a paramter list
-	 * @param start Start offset
-	 * @param end End offset
-	 * @param owner The list owner
-	 * @return The end offset after parsing
-	 * @throws EndOfFileException
-	 * @throws BacktrackException
-	 */
-	private int parameterList(int start, int end, ICPPASTParameterListOwner owner)
-			throws EndOfFileException, BacktrackException {
-		ICPPASTParameterDeclaration pd = null;
-		paramLoop: while (true) {
-			switch (LT(1)) {
-			case IToken.tRPAREN:
-			case IToken.tEOC:
-				end = consume().getEndOffset();
-				break paramLoop;
-			case IToken.tELLIPSIS:
-				consume();
-				end = consume(IToken.tRPAREN).getEndOffset();
-				owner.setVarArgs(true);
-				break paramLoop;
-			case IToken.tCOMMA:
-				if (pd == null)
-					throwBacktrack(LA(1));
-				end = consume().getEndOffset();
-				pd = null;
-				break;
-			default:
-				if (pd != null)
-					throwBacktrack(start, end - start);
-
-				pd = parameterDeclaration();
-				owner.addParameterDeclaration(pd);
-				end = calculateEndOffset(pd);
-				break;
-			}
-		}
-		// Handle ambiguity between parameter pack and varargs.
-		if (pd != null) {
-			ICPPASTDeclarator dtor = pd.getDeclarator();
-			if (dtor != null && !(dtor instanceof IASTAmbiguousDeclarator)) {
-				if (dtor.declaresParameterPack() && dtor.getNestedDeclarator() == null && dtor.getInitializer() == null
-						&& dtor.getName().getSimpleID().length == 0) {
-					((IASTAmbiguityParent) owner).replace(pd, new CPPASTAmbiguousParameterDeclaration(pd));
-				}
-			}
-		}
-		return end;
-	}
-
-	/**
 	 * Parse an array declarator starting at the square bracket.
 	 */
 	private ICPPASTArrayDeclarator arrayDeclarator(DeclarationOptions option)
diff --git a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/CPPVisitor.java b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/CPPVisitor.java
index 813e5a568c6..11cc4769f92 100644
--- a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/CPPVisitor.java
+++ b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/CPPVisitor.java
@@ -117,7 +117,6 @@ import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTConstructorInitializer;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTConversionName;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTDeclSpecifier;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTDeclarator;
-import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTDeductionGuide;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTElaboratedTypeSpecifier;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTEnumerationSpecifier;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTExplicitTemplateInstantiation;
@@ -860,9 +859,6 @@ public class CPPVisitor extends ASTQueries {
 				return null;
 			} else if (parent instanceof ICPPASTTemplateDeclaration) {
 				return CPPTemplates.createBinding(param);
-			} else if (parent instanceof ICPPASTDeductionGuide) {
-				ICPPASTDeductionGuide guide = (ICPPASTDeductionGuide) parent;
-				return new CPPParameter(name, findParameterIndex(param, guide.getParameters()));
 			}
 			return new ProblemBinding(name, IProblemBinding.SEMANTIC_INVALID_TYPE);
 		}
diff --git a/core/org.eclipse.cdt.core/src/org/eclipse/cdt/core/formatter/DefaultCodeFormatterConstants.java b/core/org.eclipse.cdt.core/src/org/eclipse/cdt/core/formatter/DefaultCodeFormatterConstants.java
index e2f3b9c0bcc..0c2e2d6e25e 100644
--- a/core/org.eclipse.cdt.core/src/org/eclipse/cdt/core/formatter/DefaultCodeFormatterConstants.java
+++ b/core/org.eclipse.cdt.core/src/org/eclipse/cdt/core/formatter/DefaultCodeFormatterConstants.java
@@ -1624,32 +1624,6 @@ public class DefaultCodeFormatterConstants {
 			+ ".formatter.insert_space_before_lambda_return"; //$NON-NLS-1$
 	/**
 	 * <pre>
-	 * FORMATTER / Option to insert a space after deduction guide arrow
-	 *     - option id:         "org.eclipse.cdt.core.formatter.insert_space_after_deduction_guide_arrow"
-	 *     - possible values:   { INSERT, DO_NOT_INSERT }
-	 *     - default:           INSERT
-	 * </pre>
-	 * @see CCorePlugin#INSERT
-	 * @see CCorePlugin#DO_NOT_INSERT
-	 * @since 7.0
-	 */
-	public static final String FORMATTER_INSERT_SPACE_AFTER_DEDUCTION_GUIDE_ARROW = CCorePlugin.PLUGIN_ID
-			+ ".formatter.insert_space_after_deduction_guide_arrow"; //$NON-NLS-1$
-	/**
-	 * <pre>
-	 * FORMATTER / Option to insert a space before deduction guide arrow
-	 *     - option id:         "org.eclipse.cdt.core.formatter.insert_space_before_deduction_guide_arrow"
-	 *     - possible values:   { INSERT, DO_NOT_INSERT }
-	 *     - default:           INSERT
-	 * </pre>
-	 * @see CCorePlugin#INSERT
-	 * @see CCorePlugin#DO_NOT_INSERT
-	 * @since 7.0
-	 */
-	public static final String FORMATTER_INSERT_SPACE_BEFORE_DEDUCTION_GUIDE_ARROW = CCorePlugin.PLUGIN_ID
-			+ ".formatter.insert_space_before_deduction_guide_arrow"; //$NON-NLS-1$
-	/**
-	 * <pre>
 	 * FORMATTER / Option to insert a space before an assignment operator
 	 *     - option id:         "org.eclipse.cdt.core.formatter.insert_space_before_assignment_operator"
 	 *     - possible values:   { INSERT, DO_NOT_INSERT }
diff --git a/core/org.eclipse.cdt.core/src/org/eclipse/cdt/core/formatter/DefaultCodeFormatterOptions.java b/core/org.eclipse.cdt.core/src/org/eclipse/cdt/core/formatter/DefaultCodeFormatterOptions.java
index 4a54656a378..dc6868739f5 100644
--- a/core/org.eclipse.cdt.core/src/org/eclipse/cdt/core/formatter/DefaultCodeFormatterOptions.java
+++ b/core/org.eclipse.cdt.core/src/org/eclipse/cdt/core/formatter/DefaultCodeFormatterOptions.java
@@ -224,14 +224,6 @@ public class DefaultCodeFormatterOptions {
 	 * @since 6.8
 	 */
 	public boolean insert_space_before_lambda_return;
-	/**
-	 * @since 7.0
-	 */
-	public boolean insert_space_after_deduction_guide_arrow;
-	/**
-	 * @since 7.0
-	 */
-	public boolean insert_space_before_deduction_guide_arrow;
 	public boolean insert_space_before_assignment_operator;
 	public boolean insert_space_before_binary_operator;
 	public boolean insert_space_before_closing_angle_bracket_in_template_arguments;
@@ -638,10 +630,6 @@ public class DefaultCodeFormatterOptions {
 				this.insert_space_after_lambda_return ? CCorePlugin.INSERT : CCorePlugin.DO_NOT_INSERT);
 		options.put(DefaultCodeFormatterConstants.FORMATTER_INSERT_SPACE_BEFORE_LAMBDA_RETURN,
 				this.insert_space_before_lambda_return ? CCorePlugin.INSERT : CCorePlugin.DO_NOT_INSERT);
-		options.put(DefaultCodeFormatterConstants.FORMATTER_INSERT_SPACE_AFTER_DEDUCTION_GUIDE_ARROW,
-				this.insert_space_after_deduction_guide_arrow ? CCorePlugin.INSERT : CCorePlugin.DO_NOT_INSERT);
-		options.put(DefaultCodeFormatterConstants.FORMATTER_INSERT_SPACE_BEFORE_DEDUCTION_GUIDE_ARROW,
-				this.insert_space_before_deduction_guide_arrow ? CCorePlugin.INSERT : CCorePlugin.DO_NOT_INSERT);
 		options.put(DefaultCodeFormatterConstants.FORMATTER_INSERT_SPACE_BEFORE_ASSIGNMENT_OPERATOR,
 				this.insert_space_before_assignment_operator ? CCorePlugin.INSERT : CCorePlugin.DO_NOT_INSERT);
 		options.put(DefaultCodeFormatterConstants.FORMATTER_INSERT_SPACE_BEFORE_BINARY_OPERATOR,
@@ -1768,18 +1756,6 @@ public class DefaultCodeFormatterOptions {
 		if (insertSpaceBeforeLambdaReturnOption != null) {
 			this.insert_space_before_lambda_return = CCorePlugin.INSERT.equals(insertSpaceBeforeLambdaReturnOption);
 		}
-		final Object insertSpaceAfterDeductionGuideOption = settings
-				.get(DefaultCodeFormatterConstants.FORMATTER_INSERT_SPACE_AFTER_DEDUCTION_GUIDE_ARROW);
-		if (insertSpaceAfterDeductionGuideOption != null) {
-			this.insert_space_after_deduction_guide_arrow = CCorePlugin.INSERT
-					.equals(insertSpaceAfterDeductionGuideOption);
-		}
-		final Object insertSpaceBeforeDeductionGuideOption = settings
-				.get(DefaultCodeFormatterConstants.FORMATTER_INSERT_SPACE_BEFORE_DEDUCTION_GUIDE_ARROW);
-		if (insertSpaceBeforeDeductionGuideOption != null) {
-			this.insert_space_before_deduction_guide_arrow = CCorePlugin.INSERT
-					.equals(insertSpaceBeforeDeductionGuideOption);
-		}
 		final Object insertSpaceBeforeAssignmentOperatorOption = settings
 				.get(DefaultCodeFormatterConstants.FORMATTER_INSERT_SPACE_BEFORE_ASSIGNMENT_OPERATOR);
 		if (insertSpaceBeforeAssignmentOperatorOption != null) {
@@ -2462,8 +2438,6 @@ public class DefaultCodeFormatterOptions {
 		this.insert_space_after_unary_operator = false;
 		this.insert_space_after_lambda_return = true;
 		this.insert_space_before_lambda_return = true;
-		this.insert_space_after_deduction_guide_arrow = true;
-		this.insert_space_before_deduction_guide_arrow = true;
 		this.insert_space_before_assignment_operator = true;
 		this.insert_space_before_binary_operator = true;
 		this.insert_space_before_closing_angle_bracket_in_template_arguments = false;
diff --git a/core/org.eclipse.cdt.core/src/org/eclipse/cdt/internal/formatter/CodeFormatterVisitor.java b/core/org.eclipse.cdt.core/src/org/eclipse/cdt/internal/formatter/CodeFormatterVisitor.java
index c32706a779e..be84be0c059 100644
--- a/core/org.eclipse.cdt.core/src/org/eclipse/cdt/internal/formatter/CodeFormatterVisitor.java
+++ b/core/org.eclipse.cdt.core/src/org/eclipse/cdt/internal/formatter/CodeFormatterVisitor.java
@@ -122,7 +122,6 @@ import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTConstructorChainInitializer;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTConstructorInitializer;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTDeclSpecifier;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTDecltypeSpecifier;
-import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTDeductionGuide;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTDeleteExpression;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTDesignatedInitializer;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTDesignator;
@@ -730,8 +729,6 @@ public class CodeFormatterVisitor extends ASTVisitor implements ICPPASTVisitor,
 				return visit((IASTFunctionDefinition) node);
 			} else if (node instanceof IASTSimpleDeclaration) {
 				return visit((IASTSimpleDeclaration) node);
-			} else if (node instanceof ICPPASTDeductionGuide) {
-				return visit((ICPPASTDeductionGuide) node);
 			} else if (node instanceof IASTASMDeclaration) {
 				return visit((IASTASMDeclaration) node);
 			} else if (node instanceof ICPPASTVisibilityLabel) {
@@ -2031,26 +2028,6 @@ public class CodeFormatterVisitor extends ASTVisitor implements ICPPASTVisitor,
 		return PROCESS_SKIP;
 	}
 
-	private int visit(ICPPASTDeductionGuide node) {
-		node.getTemplateName().accept(this);
-		final List<IASTParameterDeclaration> parameters = Arrays.asList(node.getParameters());
-		Runnable tailFormatter = new TrailingSemicolonFormatter(node);
-		final ListOptions options = new ListOptions(preferences.alignment_for_declarator_list);
-		options.fSpaceAfterSeparator = preferences.insert_space_after_comma_in_declarator_list;
-		options.fSpaceBeforeSeparator = preferences.insert_space_before_comma_in_declarator_list;
-		formatList(parameters, options, true, false, null);
-
-		if (peekNextToken() == Token.tARROW) {
-			scribe.printNextToken(Token.tARROW, preferences.insert_space_before_deduction_guide_arrow);
-			if (preferences.insert_space_after_deduction_guide_arrow) {
-				scribe.space();
-			}
-		}
-		node.getSimpleTemplateId().accept(this);
-		tailFormatter.run();
-		return PROCESS_SKIP;
-	}
-
 	private int visit(IASTSimpleDeclaration node) {
 		if (node instanceof ICPPASTStructuredBindingDeclaration) {
 			return visit((ICPPASTStructuredBindingDeclaration) node);
diff --git a/core/org.eclipse.cdt.ui.tests/ui/org/eclipse/cdt/ui/tests/text/CodeFormatterTest.java b/core/org.eclipse.cdt.ui.tests/ui/org/eclipse/cdt/ui/tests/text/CodeFormatterTest.java
index 459aab7aa09..57fe21a33df 100644
--- a/core/org.eclipse.cdt.ui.tests/ui/org/eclipse/cdt/ui/tests/text/CodeFormatterTest.java
+++ b/core/org.eclipse.cdt.ui.tests/ui/org/eclipse/cdt/ui/tests/text/CodeFormatterTest.java
@@ -4735,43 +4735,6 @@ public class CodeFormatterTest extends BaseUITestCase {
 		assertFormatterResult();
 	}
 
-	//template<class T>
-	//struct U;
-	//U()->U<int>;
-
-	//template<class T>
-	//struct U;
-	//U() -> U<int>;
-	public void testDeductionGuide() throws Exception {
-		assertFormatterResult();
-	}
-
-	//template<class T>
-	//struct U;
-	//template<class C>
-	//U(C)->U<C>;
-
-	//template<class T>
-	//struct U;
-	//template<class C>
-	//U(C) -> U<C>;
-	public void testDeductionGuideTemplate() throws Exception {
-		assertFormatterResult();
-	}
-
-	//template<class T>
-	//struct U;
-	//template<class C>
-	//explicit U(C)->U<C>;
-
-	//template<class T>
-	//struct U;
-	//template<class C>
-	//explicit U(C) -> U<C>;
-	public void testDeductionGuideExplicit() throws Exception {
-		assertFormatterResult();
-	}
-
 	//int main() {
 	//	auto f = [&](){
 	//	};
diff --git a/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/preferences/formatter/FormatterMessages.java b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/preferences/formatter/FormatterMessages.java
index 82737ec5982..7deb8d1086b 100644
--- a/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/preferences/formatter/FormatterMessages.java
+++ b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/preferences/formatter/FormatterMessages.java
@@ -212,10 +212,6 @@ final class FormatterMessages extends NLS {
 	public static String WhiteSpaceOptions_structured_binding_before_comma_in_name_list;
 	public static String WhiteSpaceOptions_structured_binding_after_comma_in_name_list;
 	public static String WhiteSpaceOptions_structured_binding_before_name_list_closing_bracket;
-	public static String WhiteSpaceTabPage_deduction_guide_declarations;
-	public static String WhiteSpaceTabPage_deduction_guide_before_arrow;
-	public static String WhiteSpaceTabPage_deduction_guide_after_arrow;
-	public static String WhiteSpaceOptions_deduction_guide_arrow_operator;
 	//	public static String WhiteSpaceOptions_before_ellipsis;
 	//	public static String WhiteSpaceOptions_after_ellipsis;
 	//	public static String WhiteSpaceOptions_return_with_parenthesized_expression;
diff --git a/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/preferences/formatter/FormatterMessages.properties b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/preferences/formatter/FormatterMessages.properties
index 94d45b8107f..6921dc869ed 100644
--- a/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/preferences/formatter/FormatterMessages.properties
+++ b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/preferences/formatter/FormatterMessages.properties
@@ -34,10 +34,6 @@ WhiteSpaceTabPage_lambda_expressions=Lambda expressions
 WhiteSpaceTabPage_lambda_before_return=before return arrow
 WhiteSpaceTabPage_lambda_after_return=after return arrow
 
-WhiteSpaceTabPage_deduction_guide_declarations=Deduction guide
-WhiteSpaceTabPage_deduction_guide_before_arrow=before arrow
-WhiteSpaceTabPage_deduction_guide_after_arrow=after arrow
-
 WhiteSpaceTabPage_classes=Types
 WhiteSpaceTabPage_classes_before_opening_brace_of_a_class=before opening brace of a class
 WhiteSpaceTabPage_classes_before_colon_of_base_clause=before colon of base clause
@@ -150,7 +146,6 @@ WhiteSpaceOptions_unary_operator=Unary operator
 WhiteSpaceOptions_prefix_operator=Prefix operator
 WhiteSpaceOptions_postfix_operator=Postfix operator
 WhiteSpaceOptions_lambda_arrow_operator=Lambda arrow operator
-WhiteSpaceOptions_deduction_guide_arrow_operator=Deduction guide arrow operator
 
 WhiteSpaceOptions_pointer=Pointer
 WhiteSpaceOptions_before_pointer=Before pointer
diff --git a/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/preferences/formatter/WhiteSpaceOptions.java b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/preferences/formatter/WhiteSpaceOptions.java
index 78116c21743..95e938b5ff6 100644
--- a/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/preferences/formatter/WhiteSpaceOptions.java
+++ b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/preferences/formatter/WhiteSpaceOptions.java
@@ -183,9 +183,6 @@ public final class WhiteSpaceOptions {
 	private final PreviewSnippet LAMBDA_PREVIEW = new PreviewSnippet(CodeFormatter.K_CLASS_BODY_DECLARATIONS,
 			"void foo() { auto f = []()->int{return 0;};}"); //$NON-NLS-1$
 
-	private final PreviewSnippet DEDUCTION_GUIDE_PREVIEW = new PreviewSnippet(CodeFormatter.K_CLASS_BODY_DECLARATIONS,
-			"template<typename T> struct U;\ntemplate<typename C>\nU(C) -> U<C>;"); //$NON-NLS-1$
-
 	private final PreviewSnippet INITIALIZER_LIST_PREVIEW = new PreviewSnippet(CodeFormatter.K_STATEMENTS,
 			"int array[]= {1, 2, 3};"); //$NON-NLS-1$
 
@@ -481,7 +478,6 @@ public final class WhiteSpaceOptions {
 		createLinkageTree(workingValues, declarations);
 		//        createConstructorTree(workingValues, declarations);
 		createLambdaDeclTree(workingValues, declarations);
-		createDeductionDeclTree(workingValues, declarations);
 		createMethodDeclTree(workingValues, declarations);
 		createExceptionSpecificationTree(workingValues, declarations);
 		createLabelTree(workingValues, declarations);
@@ -610,9 +606,6 @@ public final class WhiteSpaceOptions {
 				DefaultCodeFormatterConstants.FORMATTER_INSERT_SPACE_BEFORE_POSTFIX_OPERATOR, OPERATOR_PREVIEW);
 		createOption(parent, workingValues, FormatterMessages.WhiteSpaceOptions_lambda_arrow_operator,
 				DefaultCodeFormatterConstants.FORMATTER_INSERT_SPACE_BEFORE_LAMBDA_RETURN, LAMBDA_PREVIEW);
-		createOption(parent, workingValues, FormatterMessages.WhiteSpaceOptions_deduction_guide_arrow_operator,
-				DefaultCodeFormatterConstants.FORMATTER_INSERT_SPACE_BEFORE_DEDUCTION_GUIDE_ARROW,
-				DEDUCTION_GUIDE_PREVIEW);
 	}
 
 	private void createBeforeClosingBracketTree(Map<String, String> workingValues, final InnerNode parent) {
@@ -859,9 +852,6 @@ public final class WhiteSpaceOptions {
 				DefaultCodeFormatterConstants.FORMATTER_INSERT_SPACE_AFTER_POSTFIX_OPERATOR, OPERATOR_PREVIEW);
 		createOption(parent, workingValues, FormatterMessages.WhiteSpaceOptions_lambda_arrow_operator,
 				DefaultCodeFormatterConstants.FORMATTER_INSERT_SPACE_AFTER_LAMBDA_RETURN, LAMBDA_PREVIEW);
-		createOption(parent, workingValues, FormatterMessages.WhiteSpaceOptions_deduction_guide_arrow_operator,
-				DefaultCodeFormatterConstants.FORMATTER_INSERT_SPACE_AFTER_DEDUCTION_GUIDE_ARROW,
-				DEDUCTION_GUIDE_PREVIEW);
 	}
 
 	private void createAfterOpenBracketTree(Map<String, String> workingValues, final InnerNode parent) {
@@ -1014,19 +1004,6 @@ public final class WhiteSpaceOptions {
 		return root;
 	}
 
-	private InnerNode createDeductionDeclTree(Map<String, String> workingValues, InnerNode parent) {
-		final InnerNode root = new InnerNode(parent, workingValues,
-				FormatterMessages.WhiteSpaceTabPage_deduction_guide_declarations);
-
-		createOption(root, workingValues, FormatterMessages.WhiteSpaceTabPage_deduction_guide_before_arrow,
-				DefaultCodeFormatterConstants.FORMATTER_INSERT_SPACE_BEFORE_DEDUCTION_GUIDE_ARROW,
-				DEDUCTION_GUIDE_PREVIEW);
-		createOption(root, workingValues, FormatterMessages.WhiteSpaceTabPage_deduction_guide_after_arrow,
-				DefaultCodeFormatterConstants.FORMATTER_INSERT_SPACE_AFTER_DEDUCTION_GUIDE_ARROW,
-				DEDUCTION_GUIDE_PREVIEW);
-		return root;
-	}
-
 	private InnerNode createLambdaDeclTree(Map<String, String> workingValues, InnerNode parent) {
 		final InnerNode root = new InnerNode(parent, workingValues,
 				FormatterMessages.WhiteSpaceTabPage_lambda_expressions);