From c6176c6b67bf54e0d7932f4d9a1647ab1e21ef47 Mon Sep 17 00:00:00 2001
From: Markus Schorn <markus.schorn@windriver.com>
Date: Mon, 8 Feb 2010 13:22:48 +0000
Subject: [PATCH] Bug 294730: Default template arguments for function
 templates.

---
 .../core/parser/tests/ast2/AST2BaseTest.java  |  2 +-
 .../parser/tests/ast2/AST2TemplateTests.java  | 23 +++++++++++++++++++
 .../semantics/TemplateArgumentDeduction.java  |  3 +++
 3 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/AST2BaseTest.java b/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/AST2BaseTest.java
index 187cded860d..bc1f309d6c1 100644
--- a/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/AST2BaseTest.java
+++ b/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/AST2BaseTest.java
@@ -497,7 +497,7 @@ public class AST2BaseTest extends BaseTestCase {
     	
     	public <T extends IBinding> T assertNonProblem(String section, int len) {
     		if (len <= 0)
-    			len= section.length()-len;
+    			len= section.length()+len;
     		IBinding binding= binding(section, len);
     		if (binding instanceof IProblemBinding) {
     			IProblemBinding problem= (IProblemBinding) binding;
diff --git a/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/AST2TemplateTests.java b/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/AST2TemplateTests.java
index 93e53ecaa7f..831abef7059 100644
--- a/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/AST2TemplateTests.java
+++ b/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/AST2TemplateTests.java
@@ -4754,4 +4754,27 @@ public class AST2TemplateTests extends AST2BaseTest {
 		final String code= getAboveComment();
 		parseAndCheckBindings(code, ParserLanguage.CPP);
 	}
+	
+	//	template <class T, class U = double> void f(T t = 0, U u = 0);
+	//    void g() {
+	//        f(1, 'c');         // f<int,char>(1,'c')
+	//        f(1);              // f<int,double>(1,0)
+	//        f();               // error: T cannot be deduced
+	//        f<int>();          // f<int,double>(0,0)
+	//        f<int,char>();     // f<int,char>(0,0)
+	//    }
+	public void testDefaultTemplateArgsForFunctionTemplates_294730() throws Exception {
+		final String code= getAboveComment();
+		BindingAssertionHelper bh= new BindingAssertionHelper(code, true);
+		
+		ICPPTemplateInstance f= bh.assertNonProblem("f(1, 'c');", 1);
+		assertEquals("<int,char>", ASTTypeUtil.getArgumentListString(f.getTemplateArguments(), true));
+		f= bh.assertNonProblem("f(1);", 1);
+		assertEquals("<int,double>", ASTTypeUtil.getArgumentListString(f.getTemplateArguments(), true));
+		bh.assertProblem("f();", 1);
+		f= bh.assertNonProblem("f<int>();", -3);
+		assertEquals("<int,double>", ASTTypeUtil.getArgumentListString(f.getTemplateArguments(), true));
+		f= bh.assertNonProblem("f<int,char>();", -3);
+		assertEquals("<int,char>", ASTTypeUtil.getArgumentListString(f.getTemplateArguments(), true));
+	}
 }
diff --git a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/TemplateArgumentDeduction.java b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/TemplateArgumentDeduction.java
index f14876af10f..c3d350d1830 100644
--- a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/TemplateArgumentDeduction.java
+++ b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/TemplateArgumentDeduction.java
@@ -364,6 +364,9 @@ public class TemplateArgumentDeduction {
 					deducedArg= tpar.getDefaultValue();
 					if (deducedArg != null) {
 						deducedArg= CPPTemplates.instantiateArgument(deducedArg, tpMap, -1, null);
+						if (deducedArg != null) {
+							tpMap.put(tpar, deducedArg);
+						}
 					}
 				}
 				if (deducedArg == null)