Support writing a StringRef to a raw_ostream directly.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@76754 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Support/raw_ostream.h

@@ -15,6 +15,7 @@
 #define LLVM_SUPPORT_RAW_OSTREAM_H
 
 #include "llvm/ADT/StringExtras.h"
+#include "llvm/ADT/StringRef.h"
 #include <cassert>
 #include <cstring>
 #include <string>
@@ -151,21 +152,27 @@ public:
     return *this;
   }
 
-  raw_ostream &operator<<(const char *Str) {
-    // Inline fast path, particulary for constant strings where a
-    // sufficiently smart compiler will simplify strlen.
-
-    size_t Size = strlen(Str);
+  raw_ostream &operator<<(const StringRef &Str) {
+    // Inline fast path, particularly for strings with a known length.
+    size_t Size = Str.size();
 
     // Make sure we can use the fast path.
     if (OutBufCur+Size > OutBufEnd)
-      return write(Str, Size);
+      return write(Str.data(), Size);
 
-    memcpy(OutBufCur, Str, Size);
+    memcpy(OutBufCur, Str.data(), Size);
     OutBufCur += Size;
     return *this;
   }
 
+  raw_ostream &operator<<(const char *Str) {
+    // Inline fast path, particulary for constant strings where a sufficiently
+    // smart compiler will simplify strlen.
+
+    this->operator<<(StringRef(Str));
+    return *this;
+  }
+
   raw_ostream &operator<<(const std::string& Str) {
     write(Str.data(), Str.length());
     return *this;

unittests/ADT/StringRefTest.cpp

@@ -9,6 +9,7 @@
 
 #include "gtest/gtest.h"
 #include "llvm/ADT/StringRef.h"
+#include "llvm/Support/raw_ostream.h"
 using namespace llvm;
 
 namespace {
@@ -66,6 +67,11 @@ TEST(StringRefTest, Utilities) {
   EXPECT_TRUE(Str.startswith("he"));
   EXPECT_FALSE(Str.startswith("helloworld"));
   EXPECT_FALSE(Str.startswith("hi"));
+
+  std::string Storage;
+  raw_string_ostream OS(Storage);
+  OS << StringRef("hello");
+  EXPECT_EQ("hello", OS.str());
 }
 
 } // end anonymous namespace