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When to use symbols instead of strings in Ruby?
...iers. For Ruby < 2.2 only use symbols when they aren't generated dynamically, to avoid memory leaks.
Full answer
The only reason not to use them for identifiers that are generated dynamically is because of memory concerns.
This question is very common because many programming languages don't h...
How do I use a custom deleter with a std::unique_ptr member?
...is solution is that it doubles the overhead of every unique_ptr (they must all store the function pointer along with the pointer to the actual data), requires passing the destruction function every time, it can't inline (since the template can't specialize to the specific function, only the signatur...
How to export data as CSV format from SQL Server using sqlcmd?
...th '""' + col1 + '""' AS col1, wrapped in (doubled) double quotes or just call a stored procedure.
– MisterIsaak
Dec 11 '13 at 17:17
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How do I enable EF migrations for multiple contexts to separate databases?
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The 2nd call to Enable-Migrations is failing because the Configuration.cs file already exists. If you rename that class and file, you should be able to run that 2nd Enable-Migrations, which will create another Configuration.cs.
You ...
Is there a recommended format for multi-line imports?
...
Personally I go with parentheses when importing more than one component and sort them alphabetically. Like so:
from Tkinter import (
Button,
Canvas,
DISABLED,
END,
Entry,
Frame,
LEFT,
NORMAL,
RI...
Select multiple records based on list of Id's with linq
I have a list containing Id's of my UserProfile table. How can i select all UserProfiles based on the list of Id's i got in a var using LINQ ?
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How to add http:// if it doesn't exist in the URL?
...hat went on a swim and came back as a fish with the mindset to stop you at all costs from doing and things that might hurt you. There are so many people in the world, and you know, you have this incredible ideas and what you think is missing is motivation, But that is not true. because the way that ...
sqlalchemy unique across multiple columns
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Wang Dingwei
3,89155 gold badges2626 silver badges4141 bronze badges
answered Apr 8 '12 at 7:26
vanvan
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Define make variable at rule execution time
...r are evaluated. In order to create the directory only when out.tar is actually fired, you need to move the directory creation down into the steps:
out.tar :
$(eval TMP := $(shell mktemp -d))
@echo hi $(TMP)/hi.txt
tar -C $(TMP) cf $@ .
rm -rf $(TMP)
The eval function evaluates a...
What characters are allowed in an email address?
... not appear consecutively unless quoted (e.g. John..Doe@example.com is not allowed but "John..Doe"@example.com is allowed);
space and "(),:;<>@[\] characters are allowed with restrictions (they are only allowed inside a quoted string, as described in the paragraph below, and in addition, a b...