More of P0600 - '[[nodiscard]] in the Library' mark empty() as nodiscard in string, string_view, and the free function std::empty(). Removed tabs from <string_view>, which is why the diff is so big.

llvm-svn: 318328

7 files changed, 147 insertions, 1 deletions

diff --git a/libcxx/test/std/iterators/iterator.container/empty.array.fail.cpp b/libcxx/test/std/iterators/iterator.container/empty.array.fail.cpp
new file mode 100644
index 00000000000..a5925dee79a
--- /dev/null
+++ b/libcxx/test/std/iterators/iterator.container/empty.array.fail.cpp
@@ -0,0 +1,28 @@
+// -*- C++ -*-
+//===----------------------------------------------------------------------===//
+//
+//                     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.
+//
+//===----------------------------------------------------------------------===//
+
+// <iterator>
+
+// <iterator>
+// template <class T, size_t N> constexpr bool empty(const T (&array)[N]) noexcept;
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
+// UNSUPPORTED: clang-3.3, clang-3.4, clang-3.5, clang-3.6, clang-3.7, clang-3.8
+
+#include <vector>
+#include <iterator>
+
+#include "test_macros.h"
+
+int main ()
+{
+    int c[5];
+    std::empty(c);  // expected-error {{ignoring return value of function declared with 'nodiscard' attribute}}
+}
diff --git a/libcxx/test/std/iterators/iterator.container/empty.container.fail.cpp b/libcxx/test/std/iterators/iterator.container/empty.container.fail.cpp
new file mode 100644
index 00000000000..1773b53e7b1
--- /dev/null
+++ b/libcxx/test/std/iterators/iterator.container/empty.container.fail.cpp
@@ -0,0 +1,28 @@
+// -*- C++ -*-
+//===----------------------------------------------------------------------===//
+//
+//                     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.
+//
+//===----------------------------------------------------------------------===//
+
+// <iterator>
+
+// <iterator>
+// template <class C> constexpr auto empty(const C& c) -> decltype(c.empty());
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
+// UNSUPPORTED: clang-3.3, clang-3.4, clang-3.5, clang-3.6, clang-3.7, clang-3.8
+
+#include <vector>
+#include <iterator>
+
+#include "test_macros.h"
+
+int main ()
+{
+    std::vector<int> c;
+    std::empty(c);  // expected-error {{ignoring return value of function declared with 'nodiscard' attribute}}
+}
diff --git a/libcxx/test/std/iterators/iterator.container/empty.initializer_list.fail.cpp b/libcxx/test/std/iterators/iterator.container/empty.initializer_list.fail.cpp
new file mode 100644
index 00000000000..f6657526800
--- /dev/null
+++ b/libcxx/test/std/iterators/iterator.container/empty.initializer_list.fail.cpp
@@ -0,0 +1,28 @@
+// -*- C++ -*-
+//===----------------------------------------------------------------------===//
+//
+//                     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.
+//
+//===----------------------------------------------------------------------===//
+
+// <iterator>
+
+// <iterator>
+// template <class E> constexpr bool empty(initializer_list<E> il) noexcept;
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
+// UNSUPPORTED: clang-3.3, clang-3.4, clang-3.5, clang-3.6, clang-3.7, clang-3.8
+
+#include <initializer_list>
+#include <iterator>
+
+#include "test_macros.h"
+
+int main ()
+{
+    std::initializer_list<int> c = { 4 };
+    std::empty(c);  // expected-error {{ignoring return value of function declared with 'nodiscard' attribute}}
+}
diff --git a/libcxx/test/std/strings/basic.string/string.capacity/empty.fail.cpp b/libcxx/test/std/strings/basic.string/string.capacity/empty.fail.cpp
new file mode 100644
index 00000000000..addb02ed3cb
--- /dev/null
+++ b/libcxx/test/std/strings/basic.string/string.capacity/empty.fail.cpp
@@ -0,0 +1,28 @@
+// -*- C++ -*-
+//===----------------------------------------------------------------------===//
+//
+//                     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>
+
+// class deque
+
+// bool empty() const noexcept;
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
+// UNSUPPORTED: clang-3.3, clang-3.4, clang-3.5, clang-3.6, clang-3.7, clang-3.8
+
+#include <string>
+
+#include "test_macros.h"
+
+int main ()
+{
+    std::string c;
+    c.empty();  // expected-error {{ignoring return value of function declared with 'nodiscard' attribute}}
+}
diff --git a/libcxx/test/std/strings/basic.string/string.capacity/empty.pass.cpp b/libcxx/test/std/strings/basic.string/string.capacity/empty.pass.cpp
index fbed5c36c3f..a61a410a444 100644
--- a/libcxx/test/std/strings/basic.string/string.capacity/empty.pass.cpp
+++ b/libcxx/test/std/strings/basic.string/string.capacity/empty.pass.cpp
@@ -9,17 +9,19 @@
 
 // <string>
 
-// bool empty() const;
+// bool empty() const noexcept;
 
 #include <string>
 #include <cassert>
 
+#include "test_macros.h"
 #include "min_allocator.h"
 
 template <class S>
 void
 test(const S& s)
 {
+    ASSERT_NOEXCEPT(s.empty());
     assert(s.empty() == (s.size() == 0));
 }
 
diff --git a/libcxx/test/std/strings/string.view/string.view.capacity/capacity.pass.cpp b/libcxx/test/std/strings/string.view/string.view.capacity/capacity.pass.cpp
index d36c2788629..bb733c4fb13 100644
--- a/libcxx/test/std/strings/string.view/string.view.capacity/capacity.pass.cpp
+++ b/libcxx/test/std/strings/string.view/string.view.capacity/capacity.pass.cpp
@@ -35,6 +35,10 @@ void test1 () {
 
     {
     SV sv1;
+    ASSERT_NOEXCEPT(sv1.size());
+    ASSERT_NOEXCEPT(sv1.empty());
+    ASSERT_NOEXCEPT(sv1.max_size());
+    ASSERT_NOEXCEPT(sv1.length());
     assert ( sv1.size() == 0 );
     assert ( sv1.empty());
     assert ( sv1.size() == sv1.length());
diff --git a/libcxx/test/std/strings/string.view/string.view.capacity/empty.fail.cpp b/libcxx/test/std/strings/string.view/string.view.capacity/empty.fail.cpp
new file mode 100644
index 00000000000..da1a67b0844
--- /dev/null
+++ b/libcxx/test/std/strings/string.view/string.view.capacity/empty.fail.cpp
@@ -0,0 +1,28 @@
+// -*- C++ -*-
+//===----------------------------------------------------------------------===//
+//
+//                     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>
+
+// class string_view
+
+// bool empty() const noexcept;
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
+// UNSUPPORTED: clang-3.3, clang-3.4, clang-3.5, clang-3.6, clang-3.7, clang-3.8
+
+#include <string_view>
+
+#include "test_macros.h"
+
+int main ()
+{
+    std::string_view c;
+    c.empty();  // expected-error {{ignoring return value of function declared with 'nodiscard' attribute}}
+}