Add optimized OUString += literal overload

Change-Id: Ib34196185f90204a71598f2c659c3fddce7a0e4d

2 files changed, 42 insertions, 0 deletions

diff --git a/include/rtl/ustring.h b/include/rtl/ustring.h
index 700393694b60..2a8cd933e3e0 100644
--- a/include/rtl/ustring.h
+++ b/include/rtl/ustring.h
@@ -1434,6 +1434,30 @@ SAL_DLLPUBLIC sal_Unicode * SAL_CALL rtl_uString_getStr(
 SAL_DLLPUBLIC void SAL_CALL rtl_uString_newConcat(
         rtl_uString ** newStr, rtl_uString * left, rtl_uString * right ) SAL_THROW_EXTERN_C();
 
+/** Create a new string that is the concatenation of two other strings.
+
+    The new string does not necessarily have a reference count of 1 (in cases
+    where the ASCII string is empty), so it must not be modified without
+    checking the reference count.
+
+    @param newString
+    pointer to the new string.  The pointed-to data must be null or a valid
+    string.
+
+    @param left
+    a valid string.
+
+    @param right  must not be null and must point to memory of at least
+    \p rightLength ASCII bytes
+
+    @param rightLength  the length of the \p right string; must be non-negative
+
+    @since LibreOffice 5.1
+ */
+SAL_DLLPUBLIC void SAL_CALL rtl_uString_newConcatAsciiL(
+    rtl_uString ** newString, rtl_uString * left, char const * right,
+    sal_Int32 rightLength);
+
 /** Create a new string by replacing a substring of another string.
 
     The new string results from replacing a number of characters (count),
diff --git a/include/rtl/ustring.hxx b/include/rtl/ustring.hxx
index 387a6e8099eb..d5142afc4139 100644
--- a/include/rtl/ustring.hxx
+++ b/include/rtl/ustring.hxx
@@ -424,6 +424,24 @@ public:
         return *this;
     }
 
+    /** Append an ASCII string literal to this string.
+
+        @param literal  an 8-bit ASCII-only string literal
+
+        @since LibreOffice 5.1
+    */
+    template<typename T>
+    typename libreoffice_internal::ConstCharArrayDetector<T, OUString &>::Type
+    operator +=(T & literal) {
+        assert(
+            libreoffice_internal::ConstCharArrayDetector<T>::isValid(literal));
+        rtl_uString_newConcatAsciiL(
+            &pData, pData,
+            libreoffice_internal::ConstCharArrayDetector<T>::toPointer(literal),
+            libreoffice_internal::ConstCharArrayDetector<T>::length);
+        return *this;
+    }
+
 #ifdef LIBO_INTERNAL_ONLY // "RTL_FAST_STRING"
     /**
      @overload