1 files changed, 91 insertions, 0 deletions
diff --git a/test/std/containers/views/span.obs/size.pass.cpp b/test/std/containers/views/span.obs/size.pass.cpp
new file mode 100644
index 000000000000..c33fd3f6c61b
--- /dev/null
+++ b/test/std/containers/views/span.obs/size.pass.cpp
@@ -0,0 +1,91 @@
+// -*- 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 index_type size() const noexcept;
+//
+
+
+#include <span>
+#include <cassert>
+#include <string>
+
+#include "test_macros.h"
+
+
+template <typename Span>
+constexpr bool testConstexprSpan(Span sp, ptrdiff_t sz)
+{
+    ASSERT_NOEXCEPT(sp.size());
+    return sp.size() == sz;
+}
+
+
+template <typename Span>
+void testRuntimeSpan(Span sp, ptrdiff_t sz)
+{
+    ASSERT_NOEXCEPT(sp.size());
+    assert(sp.size() == sz);
+}
+
+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(testConstexprSpan(std::span<int>(), 0),            "");
+    static_assert(testConstexprSpan(std::span<long>(), 0),           "");
+    static_assert(testConstexprSpan(std::span<double>(), 0),         "");
+    static_assert(testConstexprSpan(std::span<A>(), 0),              "");
+    static_assert(testConstexprSpan(std::span<std::string>(), 0),    "");
+
+    static_assert(testConstexprSpan(std::span<int, 0>(), 0),         "");
+    static_assert(testConstexprSpan(std::span<long, 0>(), 0),        "");
+    static_assert(testConstexprSpan(std::span<double, 0>(), 0),      "");
+    static_assert(testConstexprSpan(std::span<A, 0>(), 0),           "");
+    static_assert(testConstexprSpan(std::span<std::string, 0>(), 0), "");
+
+    static_assert(testConstexprSpan(std::span<const int>(iArr1, 1), 1),    "");
+    static_assert(testConstexprSpan(std::span<const int>(iArr1, 2), 2),    "");
+    static_assert(testConstexprSpan(std::span<const int>(iArr1, 3), 3),    "");
+    static_assert(testConstexprSpan(std::span<const int>(iArr1, 4), 4),    "");
+    static_assert(testConstexprSpan(std::span<const int>(iArr1, 5), 5),    "");
+
+    testRuntimeSpan(std::span<int>        (), 0);
+    testRuntimeSpan(std::span<long>       (), 0);
+    testRuntimeSpan(std::span<double>     (), 0);
+    testRuntimeSpan(std::span<A>          (), 0);
+    testRuntimeSpan(std::span<std::string>(), 0);
+
+    testRuntimeSpan(std::span<int, 0>        (), 0);
+    testRuntimeSpan(std::span<long, 0>       (), 0);
+    testRuntimeSpan(std::span<double, 0>     (), 0);
+    testRuntimeSpan(std::span<A, 0>          (), 0);
+    testRuntimeSpan(std::span<std::string, 0>(), 0);
+
+    testRuntimeSpan(std::span<int>(iArr2, 1), 1);
+    testRuntimeSpan(std::span<int>(iArr2, 2), 2);
+    testRuntimeSpan(std::span<int>(iArr2, 3), 3);
+    testRuntimeSpan(std::span<int>(iArr2, 4), 4);
+    testRuntimeSpan(std::span<int>(iArr2, 5), 5);
+
+    testRuntimeSpan(std::span<int, 1>(iArr2 + 5, 1), 1);
+    testRuntimeSpan(std::span<int, 2>(iArr2 + 4, 2), 2);
+    testRuntimeSpan(std::span<int, 3>(iArr2 + 3, 3), 3);
+    testRuntimeSpan(std::span<int, 4>(iArr2 + 2, 4), 4);
+    testRuntimeSpan(std::span<int, 5>(iArr2 + 1, 5), 5);
+
+    std::string s;
+    testRuntimeSpan(std::span<std::string>(&s, (std::ptrdiff_t) 0), 0);
+    testRuntimeSpan(std::span<std::string>(&s, 1), 1);
+}