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

llvm-svn: 337804

1 files changed, 123 insertions, 0 deletions

diff --git a/libcxx/test/std/containers/views/span.cons/array.pass.cpp b/libcxx/test/std/containers/views/span.cons/array.pass.cpp
new file mode 100644
index 00000000000..80a0f07f625
--- /dev/null
+++ b/libcxx/test/std/containers/views/span.cons/array.pass.cpp
@@ -0,0 +1,123 @@
+// -*- 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>
+
+// template<size_t N>
+//     constexpr span(element_type (&arr)[N]) noexcept;
+//
+// Remarks: These constructors shall not participate in overload resolution unless:
+//   — extent == dynamic_extent || N == extent is true, and
+//   — remove_pointer_t<decltype(data(arr))>(*)[] is convertible to ElementType(*)[].
+//
+
+
+#include <span>
+#include <cassert>
+#include <string>
+
+#include "test_macros.h"
+
+
+void checkCV()
+{
+                   int   arr[] = {1,2,3};
+    const          int  carr[] = {4,5,6};
+          volatile int  varr[] = {7,8,9};
+    const volatile int cvarr[] = {1,3,5};
+
+//  Types the same (dynamic sized)
+    {
+    std::span<               int> s1{  arr};    // a span<               int> pointing at int.
+    std::span<const          int> s2{ carr};    // a span<const          int> pointing at const int.
+    std::span<      volatile int> s3{ varr};    // a span<      volatile int> pointing at volatile int.
+    std::span<const volatile int> s4{cvarr};    // a span<const volatile int> pointing at const volatile int.
+    assert(s1.size() + s2.size() + s3.size() + s4.size() == 12);
+    }
+
+//  Types the same (static sized)
+    {
+    std::span<               int,3> s1{  arr};  // a span<               int> pointing at int.
+    std::span<const          int,3> s2{ carr};  // a span<const          int> pointing at const int.
+    std::span<      volatile int,3> s3{ varr};  // a span<      volatile int> pointing at volatile int.
+    std::span<const volatile int,3> s4{cvarr};  // a span<const volatile int> pointing at const volatile int.
+    assert(s1.size() + s2.size() + s3.size() + s4.size() == 12);
+    }
+
+
+//  types different (dynamic sized)
+    {
+    std::span<const          int> s1{ arr};     // a span<const          int> pointing at int.
+    std::span<      volatile int> s2{ arr};     // a span<      volatile int> pointing at int.
+    std::span<      volatile int> s3{ arr};     // a span<      volatile int> pointing at const int.
+    std::span<const volatile int> s4{ arr};     // a span<const volatile int> pointing at int.
+    std::span<const volatile int> s5{carr};     // a span<const volatile int> pointing at const int.
+    std::span<const volatile int> s6{varr};     // a span<const volatile int> pointing at volatile int.
+    assert(s1.size() + s2.size() + s3.size() + s4.size() + s5.size() + s6.size() == 18);
+    }
+
+//  types different (static sized)
+    {
+    std::span<const          int,3> s1{ arr};   // a span<const          int> pointing at int.
+    std::span<      volatile int,3> s2{ arr};   // a span<      volatile int> pointing at int.
+    std::span<      volatile int,3> s3{ arr};   // a span<      volatile int> pointing at const int.
+    std::span<const volatile int,3> s4{ arr};   // a span<const volatile int> pointing at int.
+    std::span<const volatile int,3> s5{carr};   // a span<const volatile int> pointing at const int.
+    std::span<const volatile int,3> s6{varr};   // a span<const volatile int> pointing at volatile int.
+    assert(s1.size() + s2.size() + s3.size() + s4.size() + s5.size() + s6.size() == 18);
+    }
+}
+
+
+template <typename T>
+constexpr bool testConstexprSpan()
+{
+    constexpr T val[2] = {};
+
+    ASSERT_NOEXCEPT(std::span<const T>   {val});
+    ASSERT_NOEXCEPT(std::span<const T, 2>{val});
+    std::span<const T>    s1{val};
+    std::span<const T, 2> s2{val};
+    return
+        s1.data() == &val[0] && s1.size() == 2
+    &&  s2.data() == &val[0] && s2.size() == 2;
+}
+
+
+template <typename T>
+void testRuntimeSpan()
+{
+    T val[2] = {};
+    ASSERT_NOEXCEPT(std::span<T>   {val});
+    ASSERT_NOEXCEPT(std::span<T, 2>{val});
+    std::span<T>    s1{val};
+    std::span<T, 2> s2{val};
+    assert(s1.data() == &val[0] && s1.size() == 2);
+    assert(s2.data() == &val[0] && s2.size() == 2);
+}
+
+struct A{};
+
+int main ()
+{
+    static_assert(testConstexprSpan<int>(),    "");
+    static_assert(testConstexprSpan<long>(),   "");
+    static_assert(testConstexprSpan<double>(), "");
+    static_assert(testConstexprSpan<A>(),      "");
+
+    testRuntimeSpan<int>();
+    testRuntimeSpan<long>();
+    testRuntimeSpan<double>();
+    testRuntimeSpan<std::string>();
+    testRuntimeSpan<A>();
+
+    checkCV();
+}