string_view: add string_view capacity API libcxx tests

- taken from: llvm-mirror/libcxx@78d6a77

Author: KFilipek

tests/external/libcxx/string.view/string.view.modifiers/remove_prefix.pass.cpp

@@ -0,0 +1,83 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string_view>
+
+// void remove_prefix(size_type _n)
+
+#include <cassert>
+#include <string_view>
+
+#include "test_macros.h"
+
+template <typename CharT>
+void
+test(const CharT *s, size_t len)
+{
+	typedef std::basic_string_view<CharT> SV;
+	{
+		SV sv1(s);
+		assert(sv1.size() == len);
+		assert(sv1.data() == s);
+
+		if (len > 0) {
+			sv1.remove_prefix(1);
+			assert(sv1.size() == (len - 1));
+			assert(sv1.data() == (s + 1));
+			sv1.remove_prefix(len - 1);
+		}
+
+		assert(sv1.size() == 0);
+		sv1.remove_prefix(0);
+		assert(sv1.size() == 0);
+	}
+}
+
+#if TEST_STD_VER > 11
+constexpr size_t
+test_ce(size_t n, size_t k)
+{
+	typedef std::basic_string_view<char> SV;
+	SV sv1{"ABCDEFGHIJKL", n};
+	sv1.remove_prefix(k);
+	return sv1.size();
+}
+#endif
+
+int
+main(int, char **)
+{
+	test("ABCDE", 5);
+	test("a", 1);
+	test("", 0);
+
+	test(L"ABCDE", 5);
+	test(L"a", 1);
+	test(L"", 0);
+
+#if TEST_STD_VER >= 11
+	test(u"ABCDE", 5);
+	test(u"a", 1);
+	test(u"", 0);
+
+	test(U"ABCDE", 5);
+	test(U"a", 1);
+	test(U"", 0);
+#endif
+
+#if TEST_STD_VER > 11
+	{
+		static_assert(test_ce(5, 0) == 5, "");
+		static_assert(test_ce(5, 1) == 4, "");
+		static_assert(test_ce(5, 5) == 0, "");
+		static_assert(test_ce(9, 3) == 6, "");
+	}
+#endif
+
+	return 0;
+}

tests/external/libcxx/string.view/string.view.modifiers/remove_suffix.pass.cpp

@@ -0,0 +1,83 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string_view>
+
+// void remove_suffix(size_type _n)
+
+#include <cassert>
+#include <string_view>
+
+#include "test_macros.h"
+
+template <typename CharT>
+void
+test(const CharT *s, size_t len)
+{
+	typedef std::basic_string_view<CharT> SV;
+	{
+		SV sv1(s);
+		assert(sv1.size() == len);
+		assert(sv1.data() == s);
+
+		if (len > 0) {
+			sv1.remove_suffix(1);
+			assert(sv1.size() == (len - 1));
+			assert(sv1.data() == s);
+			sv1.remove_suffix(len - 1);
+		}
+
+		assert(sv1.size() == 0);
+		sv1.remove_suffix(0);
+		assert(sv1.size() == 0);
+	}
+}
+
+#if TEST_STD_VER > 11
+constexpr size_t
+test_ce(size_t n, size_t k)
+{
+	typedef std::basic_string_view<char> SV;
+	SV sv1{"ABCDEFGHIJKL", n};
+	sv1.remove_suffix(k);
+	return sv1.size();
+}
+#endif
+
+int
+main(int, char **)
+{
+	test("ABCDE", 5);
+	test("a", 1);
+	test("", 0);
+
+	test(L"ABCDE", 5);
+	test(L"a", 1);
+	test(L"", 0);
+
+#if TEST_STD_VER >= 11
+	test(u"ABCDE", 5);
+	test(u"a", 1);
+	test(u"", 0);
+
+	test(U"ABCDE", 5);
+	test(U"a", 1);
+	test(U"", 0);
+#endif
+
+#if TEST_STD_VER > 11
+	{
+		static_assert(test_ce(5, 0) == 5, "");
+		static_assert(test_ce(5, 1) == 4, "");
+		static_assert(test_ce(5, 5) == 0, "");
+		static_assert(test_ce(9, 3) == 6, "");
+	}
+#endif
+
+	return 0;
+}

tests/external/libcxx/string.view/string.view.modifiers/swap.pass.cpp

@@ -0,0 +1,80 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <string_view>
+
+// void swap(basic_string_view& _other) noexcept
+
+#include <cassert>
+#include <string_view>
+
+#include "test_macros.h"
+
+template <typename CharT>
+void
+test(const CharT *s, size_t len)
+{
+	typedef std::basic_string_view<CharT> SV;
+	{
+		SV sv1(s);
+		SV sv2;
+
+		assert(sv1.size() == len);
+		assert(sv1.data() == s);
+		assert(sv2.size() == 0);
+
+		sv1.swap(sv2);
+		assert(sv1.size() == 0);
+		assert(sv2.size() == len);
+		assert(sv2.data() == s);
+	}
+}
+
+#if TEST_STD_VER > 11
+constexpr size_t
+test_ce(size_t n, size_t k)
+{
+	typedef std::basic_string_view<char> SV;
+	SV sv1{"ABCDEFGHIJKL", n};
+	SV sv2{sv1.data(), k};
+	sv1.swap(sv2);
+	return sv1.size();
+}
+#endif
+
+int
+main(int, char **)
+{
+	test("ABCDE", 5);
+	test("a", 1);
+	test("", 0);
+
+	test(L"ABCDE", 5);
+	test(L"a", 1);
+	test(L"", 0);
+
+#if TEST_STD_VER >= 11
+	test(u"ABCDE", 5);
+	test(u"a", 1);
+	test(u"", 0);
+
+	test(U"ABCDE", 5);
+	test(U"a", 1);
+	test(U"", 0);
+#endif
+
+#if TEST_STD_VER > 11
+	{
+		static_assert(test_ce(2, 3) == 3, "");
+		static_assert(test_ce(5, 3) == 3, "");
+		static_assert(test_ce(0, 1) == 1, "");
+	}
+#endif
+
+	return 0;
+}