added vsprintf.h

inc/hgl/platform/os/vsprintf.h

@@ -0,0 +1,9 @@
+#ifndef HGL_VSPRINTF_INCLUDE
+#define HGL_VSPRINTF_INCLUDE
+
+#include<stdarg.h>
+namespace hgl
+{
+    template<typename T> int vsprintf(T *,const size_t,const T *,va_list va);
+}//namespace hgl
+#endif//HGL_VSPRINTF_INCLUDE