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Compelling examples of custom C++ allocators?
What are some really good reasons to ditch std::allocator in favor of a custom solution? Have you run across any situations where it was absolutely necessary for correctness, performance, scalability, etc? Any really clever examples?
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PostgreSQL create table if not exists
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CREATE TABLE myschema.mytable (i integer);
END IF;
END
$func$;
Call:
SELECT create_mytable(); -- call as many times as you want.
Notes:
The columns schemaname and tablename in pg_tables are case-sensitive. If you double-quote identifiers in the CREATE TABLE statement, you need ...
How to convert a unix timestamp (seconds since epoch) to Ruby DateTime?
...cessary instead of DateTime. So use Time.strptime("1318996912345",'%Q').to_f and you will see the milliseconds preserved, while DateTime.strptime("1318996912345",'%Q').to_f does not preserve it.
– skensell
Feb 22 '17 at 15:20
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Setting WPF image source in code
...packUri = "pack://application:,,,/AssemblyName;component/Images/icon.png";
_image.Source = new ImageSourceConverter().ConvertFromString(packUri) as ImageSource;
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Java SE 6 vs. JRE 1.6 vs. JDK 1.6 - What do these mean?
I see many different Java terms floating around. I need to install the JDK 1.6. It was my understanding that Java 6 == Java 1.6. However, when I install Java SE 6, I get a JVM that reports as version 11.0! Who can solve the madness?
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In CMake, how can I test if the compiler is Clang?
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A reliable check is to use the CMAKE_<LANG>_COMPILER_ID variables. E.g., to check the C++ compiler:
if (CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
# using Clang
elseif (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
# using GCC
elseif (CMAKE_CXX_COMPILER_ID STREQ...
How to prevent vim from creating (and leaving) temporary files?
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I added this to my _vimrc file on Windows, and I'm still getting file~ files. Am I not doing something correctly?
– FilBot3
Aug 26 '15 at 14:48
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Java: int array initializes with nonzero elements
...here it is not. Such a behavior occurs first in JDK 7u4 and also occurs in all later updates (I use 64-bit implementation). The following code throws exception:
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How does a public key verify a signature?
... add a digital signature to a document using his/her private key to essentially obtain a hash of the document, but what I do not understand is how the public key can be used to verify that signature.
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Is Using .NET 4.0 Tuples in my C# Code a Poor Design Decision?
...The consumer (not you) has to either guess or look up documentation, especially for things like Tuple<int, int>.
I would use them for private/internal members, but use result classes for public/protected members.
This answer also has some info.
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