Adapt the remaining OUString functions to std string_view

...for LIBO_INTERNAL_ONLY.  These had been missed by
1b43cceaea2084a0489db68cd0113508f34b6643 "Make many OUString functions take
std::u16string_view parameters" because they did not match the multi-overload
pattern that was addressed there, but they nevertheless benefit from being
changed just as well (witness e.g. the various resulting changes from copy() to
subView()).

This showed a conversion from OStringChar to std::string_view to be missing
(while the corresponding conversion form OUStringChar to std::u16string_view was
already present).

The improvement to loplugin:stringadd became necessary to fix

> [CPT] compilerplugins/clang/test/stringadd.cxx
> error: 'error' diagnostics expected but not seen:
>   File ~/lo/core/compilerplugins/clang/test/stringadd.cxx Line 43 (directive at ~/lo/core/compilerplugins/clang/test/stringadd.cxx:42): simplify by merging with the preceding assignment [loplugin:stringadd]
>   File ~/lo/core/compilerplugins/clang/test/stringadd.cxx Line 61 (directive at ~/lo/core/compilerplugins/clang/test/stringadd.cxx:60): simplify by merging with the preceding assignment [loplugin:stringadd]
> 2 errors generated.

Change-Id: Ie40de0616a66e60e289c1af0ca60aed6f9ecc279
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/107602
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>

3 files changed, 14 insertions, 5 deletions

diff --git a/sal/cppunittester/cppunittester.cxx b/sal/cppunittester/cppunittester.cxx
index c6fd3b9a269e..7ab54da02106 100644
--- a/sal/cppunittester/cppunittester.cxx
+++ b/sal/cppunittester/cppunittester.cxx
@@ -61,6 +61,7 @@
 #include <boost/algorithm/string.hpp>
 
 #include <algorithm>
+#include <string_view>
 
 namespace {
 
@@ -78,7 +79,7 @@ OUString getArgument(sal_Int32 index) {
     return arg;
 }
 
-std::string convertLazy(OUString const & s16) {
+std::string convertLazy(std::u16string_view s16) {
     OString s8(OUStringToOString(s16, osl_getThreadTextEncoding()));
     static_assert(sizeof (sal_Int32) <= sizeof (std::string::size_type), "must be at least the same size");
         // ensure following cast is legitimate
diff --git a/sal/osl/unx/uunxapi.cxx b/sal/osl/unx/uunxapi.cxx
index e8901784c878..1f847cfd32a5 100644
--- a/sal/osl/unx/uunxapi.cxx
+++ b/sal/osl/unx/uunxapi.cxx
@@ -17,6 +17,10 @@
  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  */
 
+#include <sal/config.h>
+
+#include <string_view>
+
 #include <config_features.h>
 
 #include "uunxapi.hxx"
@@ -31,9 +35,9 @@
 #include <osl/detail/android-bootstrap.h>
 #endif
 
-OString osl::OUStringToOString(const OUString& s)
+OString osl::OUStringToOString(std::u16string_view s)
 {
-    return OUStringToOString(s, osl_getThreadTextEncoding());
+    return rtl::OUStringToOString(s, osl_getThreadTextEncoding());
 }
 
 #if HAVE_FEATURE_MACOSX_SANDBOX
@@ -198,7 +202,7 @@ namespace {
 
 OString toOString(OString const & s) { return s; }
 
-OString toOString(OUString const & s) { return osl::OUStringToOString(s); }
+OString toOString(std::u16string_view s) { return osl::OUStringToOString(s); }
 
 template<typename T> T fromOString(OString const &) = delete;
 
diff --git a/sal/osl/unx/uunxapi.hxx b/sal/osl/unx/uunxapi.hxx
index f182b755e53b..b5c0c9ed9d41 100644
--- a/sal/osl/unx/uunxapi.hxx
+++ b/sal/osl/unx/uunxapi.hxx
@@ -20,6 +20,10 @@
 #ifndef INCLUDED_SAL_OSL_UNX_UUNXAPI_HXX
 #define INCLUDED_SAL_OSL_UNX_UUNXAPI_HXX
 
+#include <sal/config.h>
+
+#include <string_view>
+
 #include <unistd.h>
 #include <stdlib.h>
 #include <sys/types.h>
@@ -42,7 +46,7 @@ int ftruncate_with_name(int fd, sal_uInt64 uSize, rtl_String* path);
 
 namespace osl
 {
-    OString OUStringToOString(const OUString& s);
+    OString OUStringToOString(std::u16string_view s);
 
     int access(const OString& strPath, int mode);