test the remaining nfc_string member functions.

src/nfc.cc

@@ -565,11 +565,18 @@ bool UTF<CharT>::is_safe_NFC_start(std::basic_string_view<CharT> s)
 	const CharT* begin = s.data();
 	const CharT* const end = s.data() + s.size();
 	
-	const uint32_t u = parse(begin, end);
-	if(NFC_No.count(u)) return false;
-	if(NFC_Maybe.count(u)) return false;
-	
-	return true;
+	try
+	{
+		const uint32_t u = parse(begin, end);
+		if(NFC_No.count(u)) return false;
+		if(NFC_Maybe.count(u)) return false;
+		
+		return true;
+	}
+	catch(const utf_exception& ue)
+	{
+		throw illegal_utf(s, begin-s.data(), ue.reason());
+	}
 }
 
 

src/nfc.hh

@@ -96,7 +96,8 @@ public:
 		/// only forward iterator. Does a backward_iterator make sense in UTF-encoded strings?
 		typedef typename String::const_iterator  const_iterator;
 		
-		static const size_t npos = String::npos;
+		static
+		constexpr size_t npos = String::npos;
 		
 		explicit nfc_string(StringView  src);
 		explicit nfc_string(String &&   src);

test/unittest_nfcstring.cc

@@ -51,6 +51,17 @@ TEST( NfcTestString, Simple )
 	
 	// removal of the r-with-caron let the remaining ogonek combine with the e to U+0119 (E WITH OGONEK)
 	EXPECT_EQ( s.erase(11, 2).get(), "ÜberHäus\u0119" );
+	
+	EXPECT_TRUE ( s.starts_with("Üb") );
+	EXPECT_FALSE( s.starts_with("Üx") );
+	EXPECT_TRUE ( s.ends_with("s\u0119") );
+	EXPECT_FALSE( s.ends_with("ss\u0119") );
+	
+	EXPECT_EQ( s.find("Über"), 0u );
+	EXPECT_EQ( s.find("ber") , 2u );
+	EXPECT_EQ( s.find("über"), UTF8::nfc_string::npos );
+	EXPECT_EQ( s.find("Übel"), UTF8::nfc_string::npos );
+	
 }
 
 
@@ -58,4 +69,6 @@ TEST( NfcTestString, Exceptions )
 {
 	pEp::nfc_string s;
 	EXPECT_THROW( s = "Meep\xc0\x80.", pEp::illegal_utf );
+	EXPECT_THROW( s += '\377', pEp::illegal_utf );
+	
 }