ICU-1533 per Doug's review, move this to separate file

X-SVN-Rev: 6993

icu4c/source/common/charstr.h

@@ -0,0 +1,53 @@
+/*
+**********************************************************************
+*   Copyright (c) 2001, International Business Machines
+*   Corporation and others.  All Rights Reserved.
+**********************************************************************
+*   Date        Name        Description
+*   11/19/2001  aliu        Creation.
+**********************************************************************
+*/
+
+#include "unicode/utypes.h"
+#include "unicode/unistr.h"
+
+//--------------------------------------------------------------------
+// class CharString
+//
+// This is a tiny wrapper class that is used internally to make a
+// UnicodeString look like a const char*.  It can be allocated on the
+// stack.  It only creates a heap buffer if it needs to.
+//--------------------------------------------------------------------
+
+U_NAMESPACE_BEGIN
+
+class CharString {
+ public:
+    inline CharString(const UnicodeString& str);
+    inline ~CharString();
+    inline operator const char*() { return ptr; }
+ private:
+    char buf[128];
+    char* ptr;
+};
+
+inline CharString::CharString(const UnicodeString& str) {
+    // TODO This isn't quite right -- we should probably do
+    // preflighting here to determine the real length.
+    if (str.length() >= (int32_t)sizeof(buf)) {
+        ptr = new char[str.length() + 8];
+    } else {
+        ptr = buf;
+    }
+    str.extract(0, 0x7FFFFFFF, ptr, "");
+}
+
+inline CharString::~CharString() {
+    if (ptr != buf) {
+        delete[] ptr;
+    }
+}
+
+U_NAMESPACE_END
+
+//eof