Implement P0457R2: 'String Prefix and Suffix Checking' for c++2a

llvm-svn: 319687

3 files changed, 168 insertions, 0 deletions

diff --git a/libcxx/test/std/strings/basic.string/string.starts_with/starts_with.char.pass.cpp b/libcxx/test/std/strings/basic.string/string.starts_with/starts_with.char.pass.cpp
new file mode 100644
index 00000000000..4be35a76596
--- /dev/null
+++ b/libcxx/test/std/strings/basic.string/string.starts_with/starts_with.char.pass.cpp
@@ -0,0 +1,34 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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.
+//
+//===----------------------------------------------------------------------===//
+// UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
+
+// <string>
+
+//   bool starts_with(charT x) const noexcept;
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+
+int main()
+{
+    {
+    typedef std::string S;
+    S  s1 {};
+    S  s2 { "abcde", 5 };
+
+    ASSERT_NOEXCEPT(s1.starts_with('e'));
+
+    assert (!s1.starts_with('a'));
+    assert (!s1.starts_with('x'));
+    assert ( s2.starts_with('a'));
+    assert (!s2.starts_with('x'));
+    }
+}
diff --git a/libcxx/test/std/strings/basic.string/string.starts_with/starts_with.ptr.pass.cpp b/libcxx/test/std/strings/basic.string/string.starts_with/starts_with.ptr.pass.cpp
new file mode 100644
index 00000000000..5dec2156ed0
--- /dev/null
+++ b/libcxx/test/std/strings/basic.string/string.starts_with/starts_with.ptr.pass.cpp
@@ -0,0 +1,62 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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.
+//
+//===----------------------------------------------------------------------===//
+// UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
+
+// <string>
+
+//   bool starts_with(const CharT *x) const;
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+
+int main()
+{
+    {
+    typedef std::string S;
+    const char *s = "abcde";
+    S  s0 {};
+    S  s1 { s, 1 };
+    S  s2 { s, 2 };
+//     S  s3 { s, 3 };
+//     S  s4 { s, 4 };
+//     S  s5 { s, 5 };
+    S  sNot {"def", 3 };
+
+    LIBCPP_ASSERT_NOEXCEPT(s0.starts_with(""));
+
+    assert ( s0.starts_with(""));
+    assert (!s0.starts_with("a"));
+
+    assert ( s1.starts_with(""));
+    assert ( s1.starts_with("a"));
+    assert (!s1.starts_with("ab"));
+    assert (!s1.starts_with("abc"));
+    assert (!s1.starts_with("abcd"));
+    assert (!s1.starts_with("abcde"));
+    assert (!s1.starts_with("def"));
+
+    assert ( s2.starts_with(""));
+    assert ( s2.starts_with("a"));
+    assert ( s2.starts_with("ab"));
+    assert (!s2.starts_with("abc"));
+    assert (!s2.starts_with("abcd"));
+    assert (!s2.starts_with("abcde"));
+    assert (!s2.starts_with("def"));
+
+    assert ( sNot.starts_with(""));
+    assert (!sNot.starts_with("a"));
+    assert (!sNot.starts_with("ab"));
+    assert (!sNot.starts_with("abc"));
+    assert (!sNot.starts_with("abcd"));
+    assert (!sNot.starts_with("abcde"));
+    assert ( sNot.starts_with("def"));
+    }
+}
diff --git a/libcxx/test/std/strings/basic.string/string.starts_with/starts_with.string_view.pass.cpp b/libcxx/test/std/strings/basic.string/string.starts_with/starts_with.string_view.pass.cpp
new file mode 100644
index 00000000000..2dccd73dff7
--- /dev/null
+++ b/libcxx/test/std/strings/basic.string/string.starts_with/starts_with.string_view.pass.cpp
@@ -0,0 +1,72 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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.
+//
+//===----------------------------------------------------------------------===//
+// UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
+
+// <string>
+
+//   bool starts_with(string_view x) const noexcept;
+
+#include <string>
+#include <cassert>
+
+#include "test_macros.h"
+
+int main()
+{
+    {
+    typedef std::string S;
+    typedef std::string_view SV;
+    const char *s = "abcde";
+
+    S   s0;
+    S   s1  { s, 1 };
+    S   s2  { s, 2 };
+//  S   s3  { s, 3 };
+//  S   s4  { s, 4 };
+//  S   s5  { s, 5 };
+    S  sNot { "def", 3 };
+    
+    SV  sv0;
+    SV  sv1 { s, 1 };
+    SV  sv2 { s, 2 };
+    SV  sv3 { s, 3 };
+    SV  sv4 { s, 4 };
+    SV  sv5 { s, 5 };
+    SV svNot {"def", 3 };
+
+    ASSERT_NOEXCEPT(s0.starts_with(sv0));
+
+    assert ( s0.starts_with(sv0));
+    assert (!s0.starts_with(sv1));
+
+    assert ( s1.starts_with(sv0));
+    assert ( s1.starts_with(sv1));
+    assert (!s1.starts_with(sv2));
+    assert (!s1.starts_with(sv3));
+    assert (!s1.starts_with(sv4));
+    assert (!s1.starts_with(sv5));
+    assert (!s1.starts_with(svNot));
+
+    assert ( s2.starts_with(sv0));
+    assert ( s2.starts_with(sv1));
+    assert ( s2.starts_with(sv2));
+    assert (!s2.starts_with(sv3));
+    assert (!s2.starts_with(sv4));
+    assert (!s2.starts_with(sv5));
+    assert (!s2.starts_with(svNot));
+
+    assert ( sNot.starts_with(sv0));
+    assert (!sNot.starts_with(sv1));
+    assert (!sNot.starts_with(sv2));
+    assert (!sNot.starts_with(sv3));
+    assert (!sNot.starts_with(sv4));
+    assert (!sNot.starts_with(sv5));
+    assert ( sNot.starts_with(svNot));
+    }
+}