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

llvm-svn: 276238

6 files changed, 313 insertions, 0 deletions

diff --git a/libcxx/test/std/strings/string.view/string.view.cons/default.pass.cpp b/libcxx/test/std/strings/string.view/string.view.cons/default.pass.cpp
new file mode 100644
index 00000000000..54a0690e48e
--- /dev/null
+++ b/libcxx/test/std/strings/string.view/string.view.cons/default.pass.cpp
@@ -0,0 +1,46 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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 basic_string_view () noexcept;
+
+#include <string_view>
+#include <cassert>
+
+template<typename T>
+void test () {
+#if _LIBCPP_STD_VER > 11
+    {
+    constexpr T sv1;
+    static_assert ( sv1.size() == 0, "" );
+    static_assert ( sv1.empty(), "");
+    }
+#endif
+
+    {
+    T sv1;
+    assert ( sv1.size() == 0 );
+    assert ( sv1.empty());
+    }
+}
+
+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> ();
+
+}
diff --git a/libcxx/test/std/strings/string.view/string.view.cons/from_literal.pass.cpp b/libcxx/test/std/strings/string.view/string.view.cons/from_literal.pass.cpp
new file mode 100644
index 00000000000..07427b1b079
--- /dev/null
+++ b/libcxx/test/std/strings/string.view/string.view.cons/from_literal.pass.cpp
@@ -0,0 +1,64 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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 basic_string_view(const _CharT* _s)
+//    : __data (_s), __size(_Traits::length(_s)) {}
+
+
+#include <string_view>
+#include <string>
+#include <cassert>
+
+#include "constexpr_char_traits.hpp"
+
+template<typename CharT>
+size_t StrLen ( const CharT *s ) {
+    size_t retVal = 0;
+    while ( *s != 0 ) { ++retVal; ++s; }
+    return retVal;
+    }
+
+template<typename CharT>
+void test ( const CharT *s ) {
+    std::basic_string_view<CharT> sv1 ( s );
+    assert ( sv1.size() == StrLen( s ));
+    assert ( sv1.data() == s );
+    }
+
+
+int main () {
+
+    test ( "QBCDE" );
+    test ( "A" );
+    test ( "" );
+
+    test ( L"QBCDE" );
+    test ( L"A" );
+    test ( L"" );
+
+#if TEST_STD_VER >= 11
+    test ( u"QBCDE" );
+    test ( u"A" );
+    test ( u"" );
+
+    test ( U"QBCDE" );
+    test ( U"A" );
+    test ( U"" );
+#endif
+
+#if _LIBCPP_STD_VER > 11
+    {
+    constexpr std::basic_string_view<char, constexpr_char_traits<char>> sv1 ( "ABCDE" );
+    static_assert ( sv1.size() == 5, "");
+    }
+#endif
+}
diff --git a/libcxx/test/std/strings/string.view/string.view.cons/from_ptr_len.pass.cpp b/libcxx/test/std/strings/string.view/string.view.cons/from_ptr_len.pass.cpp
new file mode 100644
index 00000000000..b96bd4c72d1
--- /dev/null
+++ b/libcxx/test/std/strings/string.view/string.view.cons/from_ptr_len.pass.cpp
@@ -0,0 +1,83 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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 basic_string_view(const _CharT* _s, size_type _len)
+//      : __data (_s), __size(_len) {}
+
+
+#include <string_view>
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+
+template<typename CharT>
+void test ( const CharT *s, size_t sz ) {
+    {
+    std::basic_string_view<CharT> sv1 ( s, sz );
+    assert ( sv1.size() == sz );
+    assert ( sv1.data() == s );
+    }
+}
+
+int main () {
+
+    test ( "QBCDE", 5 );
+    test ( "QBCDE", 2 );
+    test ( "", 0 );
+#if _LIBCPP_STD_VER > 11
+    {
+    constexpr const char *s = "QBCDE";
+    constexpr std::basic_string_view<char> sv1 ( s, 2 );
+    static_assert ( sv1.size() == 2, "" );
+    static_assert ( sv1.data() == s, "" );
+    }
+#endif
+
+    test ( L"QBCDE", 5 );
+    test ( L"QBCDE", 2 );
+    test ( L"", 0 );
+#if _LIBCPP_STD_VER > 11
+    {
+    constexpr const wchar_t *s = L"QBCDE";
+    constexpr std::basic_string_view<wchar_t> sv1 ( s, 2 );
+    static_assert ( sv1.size() == 2, "" );
+    static_assert ( sv1.data() == s, "" );
+    }
+#endif
+
+#if TEST_STD_VER >= 11
+    test ( u"QBCDE", 5 );
+    test ( u"QBCDE", 2 );
+    test ( u"", 0 );
+#if _LIBCPP_STD_VER > 11
+    {
+    constexpr const char16_t *s = u"QBCDE";
+    constexpr std::basic_string_view<char16_t> sv1 ( s, 2 );
+    static_assert ( sv1.size() == 2, "" );
+    static_assert ( sv1.data() == s, "" );
+    }
+#endif
+
+    test ( U"QBCDE", 5 );
+    test ( U"QBCDE", 2 );
+    test ( U"", 0 );
+#if _LIBCPP_STD_VER > 11
+    {
+    constexpr const char32_t *s = U"QBCDE";
+    constexpr std::basic_string_view<char32_t> sv1 ( s, 2 );
+    static_assert ( sv1.size() == 2, "" );
+    static_assert ( sv1.data() == s, "" );
+    }
+#endif
+#endif
+}
diff --git a/libcxx/test/std/strings/string.view/string.view.cons/from_string.pass.cpp b/libcxx/test/std/strings/string.view/string.view.cons/from_string.pass.cpp
new file mode 100644
index 00000000000..3ca6ea16f5b
--- /dev/null
+++ b/libcxx/test/std/strings/string.view/string.view.cons/from_string.pass.cpp
@@ -0,0 +1,56 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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>
+
+// template<class Allocator>
+// basic_string_view(const basic_string<_CharT, _Traits, Allocator>& _str) noexcept
+
+
+#include <string_view>
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+
+struct dummy_char_traits : public std::char_traits<char> {};
+
+template<typename CharT, typename Traits>
+void test ( const std::basic_string<CharT, Traits> &str ) {
+    std::basic_string_view<CharT, Traits> sv1 ( str );
+    assert ( sv1.size() == str.size());
+    assert ( sv1.data() == str.data());
+}
+
+int main () {
+
+    test ( std::string("QBCDE") );
+    test ( std::string("") );
+    test ( std::string() );
+
+    test ( std::wstring(L"QBCDE") );
+    test ( std::wstring(L"") );
+    test ( std::wstring() );
+
+#if TEST_STD_VER >= 11
+    test ( std::u16string{u"QBCDE"} );
+    test ( std::u16string{u""} );
+    test ( std::u16string{} );
+
+    test ( std::u32string{U"QBCDE"} );
+    test ( std::u32string{U""} );
+    test ( std::u32string{} );
+#endif
+
+    test ( std::basic_string<char, dummy_char_traits>("QBCDE") );
+    test ( std::basic_string<char, dummy_char_traits>("") );
+    test ( std::basic_string<char, dummy_char_traits>() );
+
+}
diff --git a/libcxx/test/std/strings/string.view/string.view.cons/from_string1.fail.cpp b/libcxx/test/std/strings/string.view/string.view.cons/from_string1.fail.cpp
new file mode 100644
index 00000000000..0f33dd87bca
--- /dev/null
+++ b/libcxx/test/std/strings/string.view/string.view.cons/from_string1.fail.cpp
@@ -0,0 +1,32 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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>
+
+// template<class Allocator>
+// basic_string_view(const basic_string<_CharT, _Traits, Allocator>& _str) noexcept
+
+#include <string_view>
+#include <string>
+#include <cassert>
+
+struct dummy_char_traits : public std::char_traits<char> {};
+
+int main () {
+    using string_view = std::basic_string_view<char>;
+    using string      = std::              basic_string     <char, dummy_char_traits>;
+
+    {
+    string s{"QBCDE"};
+    string_view sv1 ( s );
+    assert ( sv1.size() == s.size());
+    assert ( sv1.data() == s.data());
+    }
+}
\ No newline at end of file
diff --git a/libcxx/test/std/strings/string.view/string.view.cons/from_string2.fail.cpp b/libcxx/test/std/strings/string.view/string.view.cons/from_string2.fail.cpp
new file mode 100644
index 00000000000..6c9ac6436ef
--- /dev/null
+++ b/libcxx/test/std/strings/string.view/string.view.cons/from_string2.fail.cpp
@@ -0,0 +1,32 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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>
+
+// template<class Allocator>
+// basic_string_view(const basic_string<_CharT, _Traits, Allocator>& _str) noexcept
+
+#include <string_view>
+#include <string>
+#include <cassert>
+
+struct dummy_char_traits : public std::char_traits<char> {};
+
+int main () {
+    using string_view = std::basic_string_view<char, dummy_char_traits>;
+    using string      = std::              basic_string     <char>;
+
+    {
+    string s{"QBCDE"};
+    string_view sv1 ( s );
+    assert ( sv1.size() == s.size());
+    assert ( sv1.data() == s.data());
+    }
+}