Implement std::string_view as described in http://wg21.link/P0254R1. Reviewed as https://reviews.llvm.org/D21459

llvm-svn: 276238

4 files changed, 295 insertions, 0 deletions

diff --git a/libcxx/test/std/strings/string.view/string.view.iterators/begin.pass.cpp b/libcxx/test/std/strings/string.view/string.view.iterators/begin.pass.cpp
new file mode 100644
index 00000000000..ba1099c62cb
--- /dev/null
+++ b/libcxx/test/std/strings/string.view/string.view.iterators/begin.pass.cpp
@@ -0,0 +1,79 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <string_view>
+
+// constexpr const_iterator begin() const;
+
+#include <string_view>
+#include <cassert>
+
+#include "test_macros.h"
+
+template <class S>
+void
+test(S s)
+{
+    const S& cs = s;
+    typename S::iterator b = s.begin();
+    typename S::const_iterator cb1 = cs.begin();
+    typename S::const_iterator cb2 = s.cbegin();
+    if (!s.empty())
+    {
+        assert(   *b ==  s[0]);
+        assert(  &*b == &s[0]);
+        assert( *cb1 ==  s[0]);
+        assert(&*cb1 == &s[0]);
+        assert( *cb2 ==  s[0]);
+        assert(&*cb2 == &s[0]);
+
+    }
+    assert(  b == cb1);
+    assert(  b == cb2);
+    assert(cb1 == cb2);
+}
+
+
+int main()
+{
+    typedef std::string_view    string_view;
+    typedef std::u16string_view u16string_view;
+    typedef std::u32string_view u32string_view;
+    typedef std::wstring_view   wstring_view;
+
+    test(string_view   ());
+    test(u16string_view());
+    test(u32string_view());
+    test(wstring_view  ());
+    test(string_view   ( "123"));
+    test(wstring_view  (L"123"));
+#if TEST_STD_VER >= 11
+    test(u16string_view{u"123"});
+    test(u32string_view{U"123"});
+#endif
+
+#if _LIBCPP_STD_VER > 11
+    {
+    constexpr string_view       sv { "123", 3 };
+    constexpr u16string_view u16sv {u"123", 3 };
+    constexpr u32string_view u32sv {U"123", 3 };
+    constexpr wstring_view     wsv {L"123", 3 };
+
+    static_assert (    *sv.begin() ==    sv[0], "" );
+    static_assert ( *u16sv.begin() == u16sv[0], "" );
+    static_assert ( *u32sv.begin() == u32sv[0], "" );
+    static_assert (   *wsv.begin() ==   wsv[0], "" );
+
+    static_assert (    *sv.cbegin() ==    sv[0], "" );
+    static_assert ( *u16sv.cbegin() == u16sv[0], "" );
+    static_assert ( *u32sv.cbegin() == u32sv[0], "" );
+    static_assert (   *wsv.cbegin() ==   wsv[0], "" );
+    }
+#endif
+}
diff --git a/libcxx/test/std/strings/string.view/string.view.iterators/end.pass.cpp b/libcxx/test/std/strings/string.view/string.view.iterators/end.pass.cpp
new file mode 100644
index 00000000000..449323e6c55
--- /dev/null
+++ b/libcxx/test/std/strings/string.view/string.view.iterators/end.pass.cpp
@@ -0,0 +1,87 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <string_view>
+
+// constexpr const_iterator end() const;
+
+#include <string_view>
+#include <cassert>
+
+#include "test_macros.h"
+
+template <class S>
+void
+test(S s)
+{
+    const S& cs = s;
+    typename S::iterator e = s.end();
+    typename S::const_iterator ce1 = cs.end();
+    typename S::const_iterator ce2 = s.cend();
+
+    if (s.empty())
+    {
+        assert(  e ==  s.begin());
+        assert(ce1 == cs.begin());
+        assert(ce2 ==  s.begin());
+    }
+    else
+    {
+        assert(  e !=  s.begin());
+        assert(ce1 != cs.begin());
+        assert(ce2 !=  s.begin());
+    }
+
+    assert(  e -  s.begin() == s.size());
+    assert(ce1 - cs.begin() == cs.size());
+    assert(ce2 - s.cbegin() == s.size());
+
+    assert(  e == ce1);
+    assert(  e == ce2);
+    assert(ce1 == ce2);
+}
+
+
+int main()
+{
+    typedef std::string_view    string_view;
+    typedef std::u16string_view u16string_view;
+    typedef std::u32string_view u32string_view;
+    typedef std::wstring_view   wstring_view;
+
+    test(string_view   ());
+    test(u16string_view());
+    test(u32string_view());
+    test(wstring_view  ());
+    test(string_view   ( "123"));
+    test(wstring_view  (L"123"));
+#if TEST_STD_VER >= 11
+    test(u16string_view{u"123"});
+    test(u32string_view{U"123"});
+#endif
+
+#if _LIBCPP_STD_VER > 11
+    {
+    constexpr string_view       sv { "123", 3 };
+    constexpr u16string_view u16sv {u"123", 3 };
+    constexpr u32string_view u32sv {U"123", 3 };
+    constexpr wstring_view     wsv {L"123", 3 };
+
+    static_assert (    sv.begin() !=    sv.end(), "" );
+    static_assert ( u16sv.begin() != u16sv.end(), "" );
+    static_assert ( u32sv.begin() != u32sv.end(), "" );
+    static_assert (   wsv.begin() !=   wsv.end(), "" );
+
+    static_assert (    sv.begin() !=    sv.cend(), "" );
+    static_assert ( u16sv.begin() != u16sv.cend(), "" );
+    static_assert ( u32sv.begin() != u32sv.cend(), "" );
+    static_assert (   wsv.begin() !=   wsv.cend(), "" );
+    }
+#endif
+}
diff --git a/libcxx/test/std/strings/string.view/string.view.iterators/rbegin.pass.cpp b/libcxx/test/std/strings/string.view/string.view.iterators/rbegin.pass.cpp
new file mode 100644
index 00000000000..381f792e5ce
--- /dev/null
+++ b/libcxx/test/std/strings/string.view/string.view.iterators/rbegin.pass.cpp
@@ -0,0 +1,61 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <string_view>
+
+// const_iterator rbegin() const;
+
+#include <string_view>
+#include <cassert>
+
+#include "test_macros.h"
+
+template <class S>
+void
+test(S s)
+{
+    const S& cs = s;
+    typename S::reverse_iterator b = s.rbegin();
+    typename S::const_reverse_iterator cb1 = cs.rbegin();
+    typename S::const_reverse_iterator cb2 = s.crbegin();
+    if (!s.empty())
+    {
+        const size_t last = s.size() - 1;
+        assert(   *b ==  s[last]);
+        assert(  &*b == &s[last]);
+        assert( *cb1 ==  s[last]);
+        assert(&*cb1 == &s[last]);
+        assert( *cb2 ==  s[last]);
+        assert(&*cb2 == &s[last]);
+
+    }
+    assert(  b == cb1);
+    assert(  b == cb2);
+    assert(cb1 == cb2);
+}
+
+
+int main()
+{
+    typedef std::string_view    string_view;
+    typedef std::u16string_view u16string_view;
+    typedef std::u32string_view u32string_view;
+    typedef std::wstring_view   wstring_view;
+
+    test(string_view   ());
+    test(u16string_view());
+    test(u32string_view());
+    test(wstring_view  ());
+    test(string_view   ( "123"));
+    test(wstring_view  (L"123"));
+#if TEST_STD_VER >= 11
+    test(u16string_view{u"123"});
+    test(u32string_view{U"123"});
+#endif
+}
diff --git a/libcxx/test/std/strings/string.view/string.view.iterators/rend.pass.cpp b/libcxx/test/std/strings/string.view/string.view.iterators/rend.pass.cpp
new file mode 100644
index 00000000000..09e7cf38c41
--- /dev/null
+++ b/libcxx/test/std/strings/string.view/string.view.iterators/rend.pass.cpp
@@ -0,0 +1,68 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <string_view>
+
+// constexpr const_iterator rend() const;
+
+#include <string_view>
+#include <cassert>
+
+#include "test_macros.h"
+
+template <class S>
+void
+test(S s)
+{
+    const S& cs = s;
+    typename S::reverse_iterator e = s.rend();
+    typename S::const_reverse_iterator ce1 = cs.rend();
+    typename S::const_reverse_iterator ce2 = s.crend();
+
+    if (s.empty())
+    {
+        assert(  e ==  s.rbegin());
+        assert(ce1 == cs.rbegin());
+        assert(ce2 ==  s.rbegin());
+    }
+    else
+    {
+        assert(  e !=  s.rbegin());
+        assert(ce1 != cs.rbegin());
+        assert(ce2 !=  s.rbegin());
+    }
+
+    assert(  e -  s.rbegin() == s.size());
+    assert(ce1 - cs.rbegin() == cs.size());
+    assert(ce2 - s.crbegin() == s.size());
+
+    assert(  e == ce1);
+    assert(  e == ce2);
+    assert(ce1 == ce2);
+}
+
+
+int main()
+{
+    typedef std::string_view    string_view;
+    typedef std::u16string_view u16string_view;
+    typedef std::u32string_view u32string_view;
+    typedef std::wstring_view   wstring_view;
+
+    test(string_view   ());
+    test(u16string_view());
+    test(u32string_view());
+    test(wstring_view  ());
+    test(string_view   ( "123"));
+    test(wstring_view  (L"123"));
+#if TEST_STD_VER >= 11
+    test(u16string_view{u"123"});
+    test(u32string_view{U"123"});
+#endif
+}