memcpy is this memcpy( writable_destination, const_source, length_in_bytes )
if you're unsure what it's doing, expand the arguments so the code is more readable (shame on whoever wrote this :) memcpy(static_cast<char*>(buffer_->Data()) + bytes_used_, data,bytes_to_save); ... auto* Destination = static_cast<char*>(buffer_->Data()); // start of buffer Destination += bytes_used_; // offset from the start, same as Destination = &Destination[bytes_used_]; memcpy(Destination, data, bytes_to_save ); So to answer your question; > with this memcpy is it copying from data which is a const char pointer n bytes_to_save into the array buffer_ No, it's copying the number of bytes *bytes_to_save* FROM *data* (from the start) > into a specific offset from the array yes, into a specific offset from the start of the array *Buffer->Data* This isn't a v8 specific question, so you may get a better response for general C/++ questions on http://www.stackoverflow.com :) On Monday, 3 September 2018 19:55:35 UTC+1, dan Med wrote: > > Can someone help me out ? > > Il giorno dom 2 set 2018 alle ore 11:26 <litoki...@gmail.com <javascript:>> > ha scritto: > >> memcpy(static_cast<char*>(buffer_->Data()) + bytes_used_, >> data,bytes_to_save); >> >> with this memcpy is it copying from data which is a const char pointer n >> bytes_to_save into the array buffer_ or into a specific offset from the >> array ? >> >> -- >> -- >> v8-users mailing list >> v8-u...@googlegroups.com <javascript:> >> http://groups.google.com/group/v8-users >> --- >> You received this message because you are subscribed to the Google Groups >> "v8-users" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to v8-users+u...@googlegroups.com <javascript:>. >> For more options, visit https://groups.google.com/d/optout. >> > -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups "v8-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.