add a route to compare a O[U]String to one code unit

Seems very awkward to create an entire temporary O[U]String just to compare it
to another when we want to know if that other contains just one char of a given
value

Change-Id: Iacd4e0d87dc5c5211fa06c61c55e1ed85b1e91f3

2 files changed, 33 insertions, 0 deletions

diff --git a/comphelper/inc/comphelper/string.hxx b/comphelper/inc/comphelper/string.hxx
index 908832789688..f5ec4a338720 100644
--- a/comphelper/inc/comphelper/string.hxx
+++ b/comphelper/inc/comphelper/string.hxx
@@ -91,6 +91,26 @@ COMPHELPER_DLLPUBLIC rtl_uString * SAL_CALL rtl_uString_alloc(sal_Int32 nLen);
  */
 COMPHELPER_DLLPUBLIC rtl_String * SAL_CALL rtl_string_alloc(sal_Int32 nLen);
 
+/** Compare an OString to a single char
+
+    @param rIn      The input OString
+    @param c        The character to compare againsg
+
+    @return         true if rIn has one char and its equal to c
+ */
+inline bool equals(const rtl::OString& rIn, sal_Char c)
+{ return rIn.getLength() == 1 && rIn[0] == c; }
+
+/** Compare an OUString to a single char
+
+    @param rIn      The input OUString
+    @param c        The character to compare againsg
+
+    @return         true if rIn has one char and its equal to c
+ */
+inline bool equals(const rtl::OUString& rIn, sal_Unicode c)
+{ return rIn.getLength() == 1 && rIn[0] == c; }
+
 /** Removes all occurrences of a character from within the source string
 
     @deprecated  Use rtl::OString::replaceAll(rtl::OString(c), rtl::OString())
diff --git a/comphelper/qa/string/test_string.cxx b/comphelper/qa/string/test_string.cxx
index 96706ace353d..96dcebd3c98f 100644
--- a/comphelper/qa/string/test_string.cxx
+++ b/comphelper/qa/string/test_string.cxx
@@ -54,6 +54,7 @@ public:
     void testDecimalStringToNumber();
     void testIsdigitAsciiString();
     void testReverseString();
+    void testEqualsString();
 
     CPPUNIT_TEST_SUITE(TestString);
     CPPUNIT_TEST(testNatural);
@@ -66,6 +67,7 @@ public:
     CPPUNIT_TEST(testDecimalStringToNumber);
     CPPUNIT_TEST(testIsdigitAsciiString);
     CPPUNIT_TEST(testReverseString);
+    CPPUNIT_TEST(testEqualsString);
     CPPUNIT_TEST_SUITE_END();
 };
 
@@ -405,6 +407,17 @@ void TestString::testReverseString()
     CPPUNIT_ASSERT(aOut == "CBA");
 }
 
+void TestString::testEqualsString()
+{
+    ::rtl::OString aIn("A");
+    CPPUNIT_ASSERT(::comphelper::string::equals(aIn, 'A'));
+    CPPUNIT_ASSERT(!::comphelper::string::equals(aIn, 'B'));
+    aIn = ::rtl::OString("AA");
+    CPPUNIT_ASSERT(!::comphelper::string::equals(aIn, 'A'));
+    aIn = ::rtl::OString();
+    CPPUNIT_ASSERT(!::comphelper::string::equals(aIn, 'A'));
+}
+
 CPPUNIT_TEST_SUITE_REGISTRATION(TestString);
 
 }