array_view was changed to span in upcoming C++20

...see <http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0122r7.pdf>
"span: bounds-safe views for sequences of objects".  o3tl::span is still an
incomplete approximation of std::span; removed those o3tl::array_view members
that are not present in std::span (and were not used in the code).

Relies on C++17 __has_include to use standard <span> where available (e.g., in
LLVM 7 libc++).

Change-Id: I82a7e246b61b2456fa6183025d25eec4121ad3c9
Reviewed-on: https://gerrit.libreoffice.org/66215
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>

3 files changed, 66 insertions, 86 deletions

diff --git a/o3tl/CppunitTest_o3tl_tests.mk b/o3tl/CppunitTest_o3tl_tests.mk
index 1dbfebdf798a..152fa48c72ca 100644
--- a/o3tl/CppunitTest_o3tl_tests.mk
+++ b/o3tl/CppunitTest_o3tl_tests.mk
@@ -27,12 +27,12 @@ $(eval $(call gb_CppunitTest_use_libraries,o3tl_tests,\
 
 $(eval $(call gb_CppunitTest_add_exception_objects,o3tl_tests,\
 	o3tl/qa/cow_wrapper_clients \
-	o3tl/qa/test-array_view \
 	o3tl/qa/test-cow_wrapper \
 	o3tl/qa/test-enumarray \
 	o3tl/qa/test-lru_map \
 	o3tl/qa/test-safeint \
 	o3tl/qa/test-sorted_vector \
+	o3tl/qa/test-span \
 	o3tl/qa/test-typed_flags \
 	o3tl/qa/test-vector_pool \
 ))
diff --git a/o3tl/qa/test-array_view.cxx b/o3tl/qa/test-array_view.cxx
deleted file mode 100644
index b82aa8cd1bf4..000000000000
--- a/o3tl/qa/test-array_view.cxx
+++ /dev/null
@@ -1,85 +0,0 @@
-/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; fill-column: 100 -*- */
-/*
- * This file is part of the LibreOffice project.
- *
- * This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/.
- */
-
-#include <sal/config.h>
-
-#include <stdexcept>
-
-#include <cppunit/TestAssert.h>
-#include <cppunit/TestFixture.h>
-#include <cppunit/extensions/HelperMacros.h>
-
-#include <o3tl/array_view.hxx>
-
-namespace {
-
-class Test: public CppUnit::TestFixture {
-private:
-    CPPUNIT_TEST_SUITE(Test);
-    CPPUNIT_TEST(testOperations);
-    CPPUNIT_TEST_SUITE_END();
-
-
-    void testOperations() {
-        int const some_data[] { 1, 2, 3 };
-        o3tl::array_view<int const> v(some_data);
-
-        CPPUNIT_ASSERT_EQUAL(1, *v.begin());
-        CPPUNIT_ASSERT_EQUAL(
-            o3tl::array_view<int>::difference_type(3), v.end() - v.begin());
-        CPPUNIT_ASSERT_EQUAL(1, *v.cbegin());
-        CPPUNIT_ASSERT_EQUAL(
-            o3tl::array_view<int>::difference_type(3), v.cend() - v.cbegin());
-        CPPUNIT_ASSERT_EQUAL(3, *v.rbegin());
-        CPPUNIT_ASSERT_EQUAL(
-            o3tl::array_view<int>::difference_type(3), v.rend() - v.rbegin());
-        CPPUNIT_ASSERT_EQUAL(3, *v.crbegin());
-        CPPUNIT_ASSERT_EQUAL(
-            o3tl::array_view<int>::difference_type(3), v.crend() - v.crbegin());
-        CPPUNIT_ASSERT_EQUAL(o3tl::array_view<int>::size_type(3), v.size());
-        CPPUNIT_ASSERT_EQUAL(o3tl::array_view<int>::size_type(3), v.length());
-        CPPUNIT_ASSERT_EQUAL(o3tl::array_view<int>::npos - 1, v.max_size());
-        CPPUNIT_ASSERT(!v.empty());
-        CPPUNIT_ASSERT_EQUAL(2, v[1]);
-        try {
-            v.at(o3tl::array_view<int>::npos);
-            CPPUNIT_FAIL("missing exception");
-        } catch (std::out_of_range &) {}
-        CPPUNIT_ASSERT_EQUAL(1, v.at(0));
-        CPPUNIT_ASSERT_EQUAL(3, v.at(2));
-        try {
-            v.at(3);
-            CPPUNIT_FAIL("missing exception");
-        } catch (std::out_of_range &) {}
-        CPPUNIT_ASSERT_EQUAL(1, v.front());
-        CPPUNIT_ASSERT_EQUAL(3, v.back());
-        CPPUNIT_ASSERT_EQUAL(1, *v.data());
-        {
-            int const d1[] { 1, 2 };
-            int const d2[] { 3, 4, 5, 6 };
-            o3tl::array_view<int const> v1( d1 );
-            o3tl::array_view<int const> v2( d2 );
-            v1.swap(v2);
-            CPPUNIT_ASSERT_EQUAL(o3tl::array_view<int>::size_type(4), v1.size());
-            CPPUNIT_ASSERT_EQUAL(o3tl::array_view<int>::size_type(2), v2.size());
-        }
-        {
-            int d1[] { 1, 2, 3 };
-            o3tl::array_view<int> v1(d1);
-            o3tl::array_view<int const> v2;
-            v2 = v1; // the special operator=
-        }
-    }
-};
-
-CPPUNIT_TEST_SUITE_REGISTRATION(Test);
-
-}
-
-/* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */
diff --git a/o3tl/qa/test-span.cxx b/o3tl/qa/test-span.cxx
new file mode 100644
index 000000000000..7ec67fa7fd91
--- /dev/null
+++ b/o3tl/qa/test-span.cxx
@@ -0,0 +1,65 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; fill-column: 100 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#include <sal/config.h>
+
+#include <utility>
+
+#include <cppunit/TestAssert.h>
+#include <cppunit/TestFixture.h>
+#include <cppunit/extensions/HelperMacros.h>
+
+#include <o3tl/span.hxx>
+
+namespace {
+
+class Test: public CppUnit::TestFixture {
+private:
+    CPPUNIT_TEST_SUITE(Test);
+    CPPUNIT_TEST(testOperations);
+    CPPUNIT_TEST_SUITE_END();
+
+
+    void testOperations() {
+        int const some_data[] { 1, 2, 3 };
+        o3tl::span<int const> v(some_data);
+
+        CPPUNIT_ASSERT_EQUAL(1, *v.begin());
+        CPPUNIT_ASSERT_EQUAL(
+            o3tl::span<int>::difference_type(3), v.end() - v.begin());
+        CPPUNIT_ASSERT_EQUAL(1, *v.cbegin());
+        CPPUNIT_ASSERT_EQUAL(
+            o3tl::span<int>::difference_type(3), v.cend() - v.cbegin());
+        CPPUNIT_ASSERT_EQUAL(3, *v.rbegin());
+        CPPUNIT_ASSERT_EQUAL(
+            o3tl::span<int>::difference_type(3), v.rend() - v.rbegin());
+        CPPUNIT_ASSERT_EQUAL(3, *v.crbegin());
+        CPPUNIT_ASSERT_EQUAL(
+            o3tl::span<int>::difference_type(3), v.crend() - v.crbegin());
+        CPPUNIT_ASSERT_EQUAL(o3tl::span<int>::index_type(3), v.size());
+        CPPUNIT_ASSERT(!v.empty());
+        CPPUNIT_ASSERT_EQUAL(2, v[1]);
+        CPPUNIT_ASSERT_EQUAL(1, *v.data());
+        {
+            int const d1[] { 1, 2 };
+            int const d2[] { 3, 4, 5, 6 };
+            o3tl::span<int const> v1( d1 );
+            o3tl::span<int const> v2( d2 );
+            std::swap(v1, v2);
+            CPPUNIT_ASSERT_EQUAL(o3tl::span<int>::index_type(4), v1.size());
+            CPPUNIT_ASSERT_EQUAL(o3tl::span<int>::index_type(2), v2.size());
+        }
+    }
+};
+
+CPPUNIT_TEST_SUITE_REGISTRATION(Test);
+
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */