SERVER-32434 operator<<(ostream,StringData)

    use boost::string_view for operator<<

2 files changed, 42 insertions, 1 deletions

diff --git a/src/mongo/base/string_data.cpp b/src/mongo/base/string_data.cpp
index 303dd3496a1..e87fdb8b63a 100644
--- a/src/mongo/base/string_data.cpp
+++ b/src/mongo/base/string_data.cpp
@@ -31,10 +31,12 @@
 
 #include <ostream>
 
+#include <boost/utility/string_view.hpp>
+
 namespace mongo {
 
 std::ostream& operator<<(std::ostream& stream, StringData value) {
-    return stream.write(value.rawData(), value.size());
+    return stream << boost::string_view(value.rawData(), value.size());
 }
 
 }  // namespace mongo
diff --git a/src/mongo/base/string_data_test.cpp b/src/mongo/base/string_data_test.cpp
index b0cfac8467a..53994e29efb 100644
--- a/src/mongo/base/string_data_test.cpp
+++ b/src/mongo/base/string_data_test.cpp
@@ -28,6 +28,9 @@
  */
 
 #include <algorithm>
+#include <functional>
+#include <iomanip>
+#include <sstream>
 #include <string>
 #include <vector>
 
@@ -325,4 +328,40 @@ TEST(StringDataFmt, Fmt) {
     ASSERT_EQUALS("-{}-"_format("abc"_sd), "-abc-");
 }
 
+TEST(Ostream, StringDataMatchesStdString) {
+    const std::string s = "xyz";
+    struct TestCase {
+        int line;
+        std::function<void(std::ostream&)> manip;
+    };
+    const TestCase testCases[] = {
+        {__LINE__, [](std::ostream& os) {}},
+        {__LINE__, [](std::ostream& os) { os << std::setw(5); }},
+        {__LINE__, [](std::ostream& os) { os << std::left << std::setw(5); }},
+        {__LINE__, [](std::ostream& os) { os << std::right << std::setw(5); }},
+        {__LINE__, [](std::ostream& os) { os << std::setfill('.') << std::left << std::setw(5); }},
+        {__LINE__, [](std::ostream& os) { os << std::setfill('.') << std::right << std::setw(5); }},
+    };
+    for (const auto& testCase : testCases) {
+        const std::string location = std::string(" at line:") + std::to_string(testCase.line);
+        struct Experiment {
+            Experiment(std::function<void(std::ostream&)> f) : putter(f) {}
+            std::function<void(std::ostream&)> putter;
+            std::ostringstream os;
+        };
+        Experiment expected{[&](std::ostream& os) { os << s; }};
+        Experiment actual{[&](std::ostream& os) { os << StringData(s); }};
+        for (auto& x : {&expected, &actual}) {
+            x->os << ">>";
+            testCase.manip(x->os);
+            x->putter(x->os);
+        }
+        // ASSERT_EQ(expected.os.str(), actual.os.str()) << location;
+        for (auto& x : {&expected, &actual}) {
+            x->os << "<<";
+        }
+        ASSERT_EQ(expected.os.str(), actual.os.str()) << location;
+    }
+}
+
 }  // namespace mongo