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When should I use malloc in C and when don't I?
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char *some_memory = "Hello World";
is creating a pointer to a string constant. That means the string "Hello World" will be somewhere in the read-only part of the memory and you just have a pointer to it. You can use the string as read-only. You cannot make changes to it. Example:
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How to convert SecureString to System.String?
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Use the System.Runtime.InteropServices.Marshal class:
String SecureStringToString(SecureString value) {
IntPtr valuePtr = IntPtr.Zero;
try {
valuePtr = Marshal.SecureStringToGlobalAllocUnicode(value);
return Marshal.PtrToStringUni(valuePtr);
} finally {
Marshal.ZeroFreeGlobalAllo...
Why is (object)0 == (object)0 different from ((object)0).Equals((object)0)?
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The reason the calls behave different is they bind to very different methods.
The == case will bind to the static reference equality operator. There are 2 independent boxed int values created hence they are not the same reference.
In the second case you bind to the insta...
How to concatenate strings in django templates?
I want to concatenate a string in a Django template tag, like:
12 Answers
12
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Is it expensive to use try-catch blocks even if an exception is never thrown?
We know that it is expensive to catch exceptions. But, is it also expensive to use a try-catch block in Java even if an exception is never thrown?
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How to dynamically load a Python class
... class, e.g. my_package.my_module.MyClass , what is the best possible way to load it?
10 Answers
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When to use symbols instead of strings in Ruby?
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TL;DR
A simple rule of thumb is to use symbols every time you need internal identifiers. 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...
How to sparsely checkout only one single file from a git repository?
...Paul Brannan's answer:
git archive --format=tar --remote=origin HEAD:path/to/directory -- filename | tar -O -xf -
But: in 2013, that was no longer possible for remote https://github.com URLs.
See the old page "Can I archive a repository?"
The current (2018) page "About archiving content and data...
Non-recursive depth first search algorithm
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DFS:
list nodes_to_visit = {root};
while( nodes_to_visit isn't empty ) {
currentnode = nodes_to_visit.take_first();
nodes_to_visit.prepend( currentnode.children );
//do something
}
BFS:
list nodes_to_visit = {root};
while( nodes_to_...
What's the difference between the Dependency Injection and Service Locator patterns?
...ciple of inversion of control. That is, that an object should not know how to construct its dependencies.
15 Answers
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