Merge pull request #63245 from whiteio/whiteio/add-customstringconvertible-conformance-to-std-string

Make std::string conform to CustomStringConvertible

Author: egorzhdan

stdlib/public/Cxx/std/String.swift

@@ -35,6 +35,12 @@ extension std.string: CustomDebugStringConvertible {
   }
 }
 
+extension std.string: CustomStringConvertible {
+  public var description: String {
+    return String(cxxString: self)
+  }
+}
+
 extension String {
   /// Creates a String having the same content as the given C++ string.
   ///

test/Interop/Cxx/stdlib/overlay/std-string-overlay.swift

@@ -35,6 +35,14 @@ StdStringOverlayTestSuite.test("std::string <=> Swift.String") {
   expectEqual(cxx6.size(), 7)
   let swift6 = String(cxxString: cxx6)
   expectEqual(swift6, "xyz\0abc")
+
+  var cxx7 = std.string()
+  let bytes: [UInt8] = [0xE1, 0xC1, 0xAC]
+  for byte in bytes {
+    cxx7.push_back(CChar(bitPattern: byte))
+  }
+  let swift7 = String(cxxString: cxx7)
+  expectEqual(swift7, "���")
 }
 
 StdStringOverlayTestSuite.test("std::string as Swift.CustomDebugStringConvertible") {
@@ -71,4 +79,19 @@ StdStringOverlayTestSuite.test("std::string as Swift.Sequence") {
   expectEqual(97 + 98 + 99 + 49 + 50 + 51, sum)
 }
 
+StdStringOverlayTestSuite.test("std::string as CustomStringConvertible") {
+  let cxx1 = std.string()
+  expectEqual(cxx1.description, "")
+
+  let cxx2 = std.string("something123")
+  expectEqual(cxx2.description, "something123")
+
+  let bytes: [UInt8] = [0xE1, 0xC1, 0xAC]
+  var cxx3 = std.string()
+  for byte in bytes {
+    cxx3.push_back(CChar(bitPattern: byte))
+  }
+  expectEqual(cxx3.description, "���")
+}
+
 runAllTests()