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What is recursion and when should I use it?

... However, the real problem is in step #1. When many programs start, they allocate a single chunk of memory for their stack, and when they run out of that memory (often, but not always due to recursion), the program crashes due to a stack overflow. So in these languages recursion is slower and it ...
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Uses for Optional

...) { return Optional.ofNullable(parent); }. This looks expensive because it allocates an Optional every time! But if the caller unpacks it immediately, the object is extremely short-lived and is never promoted out of eden space. It might possibly even be eliminated by the JIT's escape analysis. The b...
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What is the recommended approach towards multi-tenant databases in MongoDB?

...decided not to have a database per customer because of the way MongoDB allocates its data files. Each database uses it’s own set of files: The first file for a database is dbname.0, then dbname.1, etc. dbname.0 will be 64MB, dbname.1 128MB, etc., up to 2GB. Once the fil...
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Does const mean thread-safe in C++11?

...too artificial, you could mentally replace int by a very large dynamically allocated integer which is inherently non thread-safe and for which multiplications are extremely costly.] The member-function area is no longer thread-safe, it is doing writes now and is not internally synchronized. Is it a ...
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C++11 rvalues and move semantics confusion (return statement)

..., a new vector is actually constructed in the copy constructor and data is allocated, but the bulk of the data array is only copied by copying the pointer (essentially). The copy elision avoids 100% of all copies. – Mark Lakata Dec 11 '14 at 1:26 ...
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Why can templates only be implemented in the header file?

...at would add overhead such as boxing, needing to pass function pointers to allocators and constructors, etc. The intention of C++ templates is to avoid having to write nearly identical class MyClass_int, class MyClass_float, etc, but to still be able to end up with compiled code that is mostly as if...
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When is memoization automatic in GHC Haskell?

...ency of 5356 bytes regardless of optimization, by the way (with less total allocation when -O2 is used). – Ed'ka Oct 17 '10 at 10:41 1 ...
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When to use symbols instead of strings in Ruby?

...utput, you should go with strings, even if it appears more than once, even allocating two different objects in memory. Here's the reasoning: Printing the symbols will be slower than printing strings because they are cast to strings. Having lots of different symbols will increase the overall mem...
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Does C++ support 'finally' blocks? (And what's this 'RAII' I keep hearing about?)

...t even managed languages provide a finally-block despite resources being deallocated automatically by the garbage collector anyway? Actually, languages based on Garbage collectors need "finally" more. A garbage collector does not destroy your objects in a timely manner, so it can not be relied upo...
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Use of Finalize/Dispose method in C#

... that the resources have been disposed of and its ok to release the memory allocated for them. } } finally { // explicitly call the base class Dispose implementation base.Dispose( isDisposing ); this.IsDisposed = true; } } //TODO Uncomment this cod...