[libcxx] Fix max_size() across all containers

Summary: The `max_size()` method of containers should respect both the allocator's reported `max_size` and the range of the `difference_type`. This patch makes all containers choose the smallest of those two values.

Reviewers: mclow.lists, EricWF

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D26885

llvm-svn: 287729

1 files changed, 47 insertions, 0 deletions

diff --git a/libcxx/test/std/containers/sequences/deque/deque.capacity/max_size.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.capacity/max_size.pass.cpp
new file mode 100644
index 00000000000..11ce9d2f689
--- /dev/null
+++ b/libcxx/test/std/containers/sequences/deque/deque.capacity/max_size.pass.cpp
@@ -0,0 +1,47 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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.
+//
+//===----------------------------------------------------------------------===//
+
+// <deque>
+
+// size_type max_size() const;
+
+#include <cassert>
+#include <deque>
+#include <limits>
+#include <type_traits>
+
+#include "test_allocator.h"
+#include "test_macros.h"
+
+int main() {
+  {
+    typedef limited_allocator<int, 10> A;
+    typedef std::deque<int, A> C;
+    C c;
+    assert(c.max_size() <= 10);
+    LIBCPP_ASSERT(c.max_size() == 10);
+  }
+  {
+    typedef limited_allocator<int, (size_t)-1> A;
+    typedef std::deque<int, A> C;
+    const C::difference_type max_dist =
+        std::numeric_limits<C::difference_type>::max();
+    C c;
+    assert(c.max_size() <= max_dist);
+    LIBCPP_ASSERT(c.max_size() == max_dist);
+  }
+  {
+    typedef std::deque<char> C;
+    const C::difference_type max_dist =
+        std::numeric_limits<C::difference_type>::max();
+    C c;
+    assert(c.max_size() <= max_dist);
+    assert(c.max_size() <= alloc_max_size(c.get_allocator()));
+  }
+}