fix(format): Poco::format and C++20 #3733

Foundation/include/Poco/Format.h

@@ -106,20 +106,26 @@ std::string Foundation_API format(const std::string& fmt, const Any& value);
 	///     std::string s2 = format("second: %[1]d, first: %[0]d", 1, 2);
 
 void Foundation_API format(std::string& result, const char *fmt, const std::vector<Any>& values);
-	/// Supports a variable number of arguments and is used by
+	/// Supports a variable number of arguments.
-	/// all other variants of format().
 
 void Foundation_API format(std::string& result, const std::string& fmt, const std::vector<Any>& values);
+	/// Supports a variable number of arguments.
+
+inline void formatAny(std::string& result, const std::string& fmt, const std::vector<Any>& values)
 	/// Supports a variable number of arguments and is used by
 	/// all other variants of format().
+{
+	format(result, fmt, values);
+}
 
+inline void formatAny(std::string& result, const char *fmt, const std::vector<Any>& values)
+	/// Supports a variable number of arguments and is used by
+	/// all other variants of format().
+{
+	format(result, fmt, values);
+}
 
-template <
+template <typename T, typename... Args>
-	typename T,
-#ifdef __cpp_lib_remove_cvref
-	typename std::enable_if_t<!std::is_same_v<std::remove_cvref_t<T>, std::vector<Any>>>,
-#endif
-	typename... Args>
 void format(std::string& result, const std::string& fmt, T arg1, Args... args)
 	/// Appends the formatted string to result.
 {
@@ -127,16 +133,11 @@ void format(std::string& result, const std::string& fmt, T arg1, Args... args)
 	values.reserve(sizeof...(Args) + 1);
 	values.emplace_back(arg1);
 	values.insert(values.end(), { args... });
-	format(result, fmt, values);
+	formatAny(result, fmt, values);
 }
 
 
-template <
+template <typename T, typename... Args>
-	typename T,
-#ifdef __cpp_lib_remove_cvref
-	typename std::enable_if_t<!std::is_same_v<std::remove_cvref_t<T>, std::vector<Any>>>,
-#endif
-	typename... Args>
 void format(std::string& result, const char* fmt, T arg1, Args... args)
 	/// Appends the formatted string to result.
 {
@@ -144,16 +145,11 @@ void format(std::string& result, const char* fmt, T arg1, Args... args)
 	values.reserve(sizeof...(Args) + 1);
 	values.emplace_back(arg1);
 	values.insert(values.end(), { args... });
-	format(result, fmt, values);
+	formatAny(result, fmt, values);
 }
 
 
-template <
+template <typename T, typename... Args>
-	typename T,
-#ifdef __cpp_lib_remove_cvref
-	typename std::enable_if_t<!std::is_same_v<std::remove_cvref_t<T>, std::vector<Any>>>,
-#endif
-	typename... Args>
 std::string format(const std::string& fmt, T arg1, Args... args)
 	/// Returns the formatted string.
 {
@@ -162,17 +158,12 @@ std::string format(const std::string& fmt, T arg1, Args... args)
 	values.emplace_back(arg1);
 	values.insert(values.end(), { args... });
 	std::string result;
-	format(result, fmt, values);
+	formatAny(result, fmt, values);
 	return result;
 }
 
 
-template <
+template <typename T, typename... Args>
-	typename T,
-#ifdef __cpp_lib_remove_cvref
-	typename std::enable_if_t<!std::is_same_v<std::remove_cvref_t<T>, std::vector<Any>>>,
-#endif
-	typename... Args>
 std::string format(const char* fmt, T arg1, Args... args)
 	/// Returns the formatted string.
 {
@@ -181,7 +172,7 @@ std::string format(const char* fmt, T arg1, Args... args)
 	values.emplace_back(arg1);
 	values.insert(values.end(), { args... });
 	std::string result;
-	format(result, fmt, values);
+	formatAny(result, fmt, values);
 	return result;
 }
 

Foundation/testsuite/src/FormatTest.cpp

@@ -20,6 +20,7 @@ using Poco::format;
 using Poco::BadCastException;
 using Poco::Int64;
 using Poco::UInt64;
+using Poco::Any;
 
 
 FormatTest::FormatTest(const std::string& name): CppUnit::TestCase(name)
@@ -453,6 +454,27 @@ void FormatTest::testIndex()
 }
 
 
+void FormatTest::testAny()
+{
+	Any a = 42;
+	std::string s(format("%d", a));
+	assertTrue (s == "42");
+
+	a = std::string("42");
+	s = format("%s", a);
+	assertTrue (s == "42");
+
+	a = 42.;
+	s = format("%f", a);
+	assertTrue (s.find("42.0") == 0);
+
+	s.clear();
+	std::vector<Any> av{ 42, std::string("42"), 42. };
+	format(s, "%d '%s' %f", av);
+	assertTrue (s.find("42 '42' 42.0") == 0);
+}
+
+
 void FormatTest::setUp()
 {
 }
@@ -476,6 +498,7 @@ CppUnit::Test* FormatTest::suite()
 	CppUnit_addTest(pSuite, FormatTest, testString);
 	CppUnit_addTest(pSuite, FormatTest, testMultiple);
 	CppUnit_addTest(pSuite, FormatTest, testIndex);
+	CppUnit_addTest(pSuite, FormatTest, testAny);
 
 	return pSuite;
 }

Foundation/testsuite/src/FormatTest.h

@@ -30,6 +30,7 @@ public:
 	void testString();
 	void testMultiple();
 	void testIndex();
+	void testAny();
 
 	void setUp();
 	void tearDown();