From: xtkoba+ruby@... Date: 2021-03-26T11:27:08+00:00 Subject: [ruby-core:103038] [Ruby master Misc#17751] Do these instructions (<<, +, [0..n]) modify the original string without creating copies? Issue #17751 has been updated by xtkoba (Tee KOBAYASHI). I understand that in the last case a copy of the content of `str` is not created, although it can trigger `memmove` when the assignment changes the length of the string. BTW is it really necessary to hold the whole data in one string? I would create a new class to hold them, or simply write `data = [header, str]` or `data = {:header => header, :str => str}` or something. ---------------------------------------- Misc #17751: Do these instructions (<<,+,[0..n]) modify the original string without creating copies? https://bugs.ruby-lang.org/issues/17751#change-91101 * Author: stiuna (Juan Gregorio) * Status: Open * Priority: Normal ---------------------------------------- In my program a string increases considerably in size inside a loop, at the end of that loop a header is created that will have to go to the beginning of that string. During the whole loop: ``` ruby str << "some data" ``` At the end: ``` ruby header = "other data" str = header + str ``` I understand that using (+) creates a copy to then modify the original variable, that is not desirable, I would like to do something similar to (<<), which I understand does not create copies. If I do this: ``` ruby header << str ``` I would have two variables with a very large size. I also have this other code and I don't know if it is an "in place" modifier: ``` ruby str = "12345" str[0..2] = "" #s => 45 ``` In short, I want to know what instructions I should use to remove a given range from a string and how to concatenate to both the beginning and end of the target string without having to create copies. -- https://bugs.ruby-lang.org/ Unsubscribe: