Add convenience _FORMAT macro

include/atrip/Utils.hpp

@@ -80,6 +80,16 @@ struct Timer {
 using Timings = std::map<std::string, Timer>;
 // Chrono:1 ends here
 
+//  A nice handy macro to do formatting
+#define _FORMAT(_fmt, ...)                                    \
+  ([&] (void) -> std::string {                                \
+     int _sz = std::snprintf(nullptr, 0, _fmt, __VA_ARGS__);  \
+     std::vector<char>  _out(_sz  +  1);                      \
+     std::snprintf(&_out[0], _out.size(), _fmt, __VA_ARGS__); \
+     return std::string(_out.data());                         \
+   })()
+
+
 // [[file:~/cuda/atrip/atrip.org::*Epilog][Epilog:1]]
 }
 // Epilog:1 ends here