Merge pull request #74426 from apple/susmonteiro/cxx-span

[cxx-interop] Add `std::span` tests

Author: susmonteiro

test/Interop/Cxx/stdlib/Inputs/module.modulemap

@@ -4,6 +4,12 @@ module StdVector {
   export *
 }
 
+module StdSpan {
+  header "std-span.h"
+  requires cplusplus
+  export *
+}
+
 module StdMap {
   header "std-map.h"
   requires cplusplus

test/Interop/Cxx/stdlib/Inputs/std-span.h

@@ -0,0 +1,21 @@
+#ifndef TEST_INTEROP_CXX_STDLIB_INPUTS_STD_SPAN_H
+#define TEST_INTEROP_CXX_STDLIB_INPUTS_STD_SPAN_H
+
+#include <cstddef>
+#include <string>
+#include <span>
+
+using Span = std::span<const int>;
+using SpanOfString = std::span<const std::string>;
+
+static int iarray[]{1, 2, 3};
+static std::string sarray[]{"", "ab", "abc"};
+static Span ispan = {iarray};
+static SpanOfString sspan = {sarray};
+
+inline Span initSpan() { 
+  const int a[]{1, 2, 3};
+  return Span(a);
+}
+
+#endif // TEST_INTEROP_CXX_STDLIB_INPUTS_STD_SPAN_H

test/Interop/Cxx/stdlib/use-std-span.swift

@@ -0,0 +1,44 @@
+// RUN: %target-run-simple-swift(-I %S/Inputs -Xfrontend -enable-experimental-cxx-interop -Xcc -std=c++20)
+
+// FIXME swift-ci linux tests do not support std::span
+// UNSUPPORTED: OS=linux-gnu
+
+import StdlibUnittest
+#if !BRIDGING_HEADER
+import StdSpan
+#endif
+import CxxStdlib
+
+var StdSpanTestSuite = TestSuite("StdSpan")
+
+StdSpanTestSuite.test("EmptySpan") {
+  let s = Span()
+  expectEqual(s.size(), 0)
+  expectTrue(s.empty())
+}
+
+StdSpanTestSuite.test("InitSpan") {
+  let s = initSpan()
+  expectEqual(s.size(), 3)
+  expectFalse(s.empty())
+}
+
+StdSpanTestSuite.test("InitStaticSpan") {
+  expectEqual(ispan.size(), 3)
+  expectFalse(ispan.empty())
+
+  expectEqual(ispan[0], 1)
+  expectEqual(ispan[1], 2)
+  expectEqual(ispan[2], 3)
+}
+
+StdSpanTestSuite.test("InitStringSpan") {
+  expectEqual(sspan.size(), 3)
+  expectFalse(sspan.empty())
+
+  expectEqual(sspan[0], "")
+  expectEqual(sspan[1], "ab")
+  expectEqual(sspan[2], "abc")
+}
+
+runAllTests()