Implement <span>. Reviewed as https://reviews.llvm.org/D49338

llvm-svn: 337804

1 files changed, 73 insertions, 0 deletions

diff --git a/libcxx/test/std/containers/views/span.obs/empty.pass.cpp b/libcxx/test/std/containers/views/span.obs/empty.pass.cpp
new file mode 100644
index 00000000000..a48c0d02494
--- /dev/null
+++ b/libcxx/test/std/containers/views/span.obs/empty.pass.cpp
@@ -0,0 +1,73 @@
+// -*- C++ -*-
+//===------------------------------ span ---------------------------------===//
+//
+//                     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 
+
+// <span>
+
+// constexpr bool empty() const noexcept;
+//
+
+
+#include <span>
+#include <cassert>
+#include <string>
+
+#include "test_macros.h"
+
+struct A{};
+constexpr int iArr1[] = { 0,  1,  2,  3,  4,  5,  6,  7,  8,  9};
+          int iArr2[] = {10, 11, 12, 13, 14, 15, 16, 17, 18, 19};
+
+int main ()
+{
+    static_assert( noexcept(std::span<int>   ().empty()), "");
+    static_assert( noexcept(std::span<int, 0>().empty()), "");
+
+
+    static_assert( std::span<int>().empty(),            "");
+    static_assert( std::span<long>().empty(),           "");
+    static_assert( std::span<double>().empty(),         "");
+    static_assert( std::span<A>().empty(),              "");
+    static_assert( std::span<std::string>().empty(),    "");
+
+    static_assert( std::span<int, 0>().empty(),         "");
+    static_assert( std::span<long, 0>().empty(),        "");
+    static_assert( std::span<double, 0>().empty(),      "");
+    static_assert( std::span<A, 0>().empty(),           "");
+    static_assert( std::span<std::string, 0>().empty(), "");
+
+    static_assert(!std::span<const int>(iArr1, 1).empty(), "");
+    static_assert(!std::span<const int>(iArr1, 2).empty(), "");
+    static_assert(!std::span<const int>(iArr1, 3).empty(), "");
+    static_assert(!std::span<const int>(iArr1, 4).empty(), "");
+    static_assert(!std::span<const int>(iArr1, 5).empty(), "");
+    
+    assert( (std::span<int>().empty()           ));
+    assert( (std::span<long>().empty()          ));
+    assert( (std::span<double>().empty()        ));
+    assert( (std::span<A>().empty()             ));
+    assert( (std::span<std::string>().empty()   ));
+
+    assert( (std::span<int, 0>().empty()        ));
+    assert( (std::span<long, 0>().empty()       ));
+    assert( (std::span<double, 0>().empty()     ));
+    assert( (std::span<A, 0>().empty()          ));
+    assert( (std::span<std::string, 0>().empty()));
+
+    assert(!(std::span<int, 1>(iArr2, 1).empty()));
+    assert(!(std::span<int, 2>(iArr2, 2).empty()));
+    assert(!(std::span<int, 3>(iArr2, 3).empty()));
+    assert(!(std::span<int, 4>(iArr2, 4).empty()));
+    assert(!(std::span<int, 5>(iArr2, 5).empty()));
+
+    std::string s;
+    assert( ((std::span<std::string>(&s, (std::ptrdiff_t) 0)).empty()));
+    assert(!((std::span<std::string>(&s, 1).empty())));
+}