Fix util::ostringstream, fix pretty-printing, stub out new globals

luprex/cpp/core/util.hpp

@@ -350,7 +350,32 @@ inline eng::string ss(const ARGS & ... args) {
     return oss.str();
 }
 
-
+// util::ostringstream
+//
+// This is a variant of ostringstream in which it is possible
+// to get the contents without copying.   To get the contents
+// without copying, use oss.size() and oss.c_str()
+//
+class ostringstream : public eng::ostringstream {
+    class rstringbuf : public std::basic_stringbuf<char_type, traits_type, allocator_type> {
+    public:
+        char *eback() const { return std::streambuf::eback(); }
+        char *pptr() const { return std::streambuf::pptr(); }
+    };
+    rstringbuf rstringbuf_;
+public:
+    ostringstream() {
+        std::basic_ostream<char>::rdbuf(&rstringbuf_);
+    }
+    std::string_view view() const {
+        char *p = rstringbuf_.eback();
+        size_t size = rstringbuf_.pptr() - p;
+        return std::string_view(p, size);
+    }
+    eng::string str() const {
+        return rstringbuf_.str();
+    }
+};
 
 // dprintf
 //