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• std::unique_lock - Cannot lock twice? - 1 Update
• "Indirect" Addressing - 1 Update

std::unique_lock - Cannot lock twice?

Christopher <christopherpisz@gmail.com>: Mar 08 02:57PM -0800 I debugged an application to the following scenario:     #include <mutex>   std::mutex g_mutex;   int main() {   std::unique_lock<std::mutex> lock(g_mutex); lock.release(); lock.lock(); lock.release(); }     This throws on the second attempt to lock. I thought the difference between unique lock and lock guard was that unique lock allowed manually locking and unlocking. We cannot lock it twice?

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"Indirect" Addressing

Mike Copeland <mrc2323@cox.net>: Mar 08 02:56PM -0700 In article <o9pt5l$f6j$1@dont-email.me>, alf.p.steinbach+usenet@gmail.com says...   > It seems that for BNoffset you want it to get the index of the last > occurrence of "NO." or "BIB" in the array.   > Is this correct, and if so, what do you use that for?   No, that's not quite what I'm doing. I'm processing a CSV file that has a reader record (the constants). I want to determine the offset for each data field in data record so that I know how to process the data values. For example, if Column 2 has the "BIB" values, I want to process that data with a routine that's coded for whatever the "BNoffset" index is for that file. That is, when I process the "Bib#" field data, I need to know that the data for that processing is in the 2nd field in the data records. Furthermore, the "Bib#" field can be identified in various files by "NO.", "BIB", or other header names. So, for each fiel's processing I need to scan the header, determine which columns have the data values I want to process, and be able to access the data from a parsed CSV records. So, as I scan the header record, as I find a match on specific constant values, I want to save the column offset in the named offset values (BNoffset, OPoffset, FNoffset, etc.). There are many fields and even more field names, and any field can be in any column of the file. 8<{{ Does this help?   --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

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