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Why doesn't C++ have a garbage collector?
...calls!
Languages with GC have two work arounds:
don't use GC when stack allocation is sufficient: it's normally for performance issues, but in our case it really helps since the scope defines the lifetime
using construct... but it's explicit (weak) RAII while in C++ RAII is implicit so that the u...
C++ - passing references to std::shared_ptr or boost::shared_ptr
... a shared_ptr continuing to be non-null throughout, is for the function to allocate its own true shared_ptr, rather than relying on a reference to an existing shared_ptr.
The downside is that copied a shared_ptr is not free: even "lock-free" implementations have to use an interlocked operation to h...
How do function pointers in C work?
...eir respective functions:
String newString()
{
String self = (String)malloc(sizeof(struct String_Struct));
self->get = &getString;
self->set = &setString;
self->length = &lengthString;
self->set(self, "");
return self;
}
For example, the getStrin...
What's the fastest way to merge/join data.frames in R?
...ata.table is actually timing base functions colMeans and cbind (the memory allocation and copying induced by using those functions). There are good and bad ways of using data.table, too.
benchmark(replications = 1, order = "elapsed",
aggregate = aggregate(d[c("x", "y")], d[c("g1", "g2")], mean),...
How are strings passed in .NET?
... Each instance is immutable. When you change the value of a string you are allocating a new string in memory.
So only the reference is passed to your function, but when the string is edited it becomes a new instance and doesn't modify the old instance.
...
JavaScript hashmap equivalent
...ou can control indexing done by JavaScript without heavy lifting of memory allocation, and overflow handling.
Of course, if you truly want the "industrial-grade solution", you can build a class parameterized by the key function, and with all the necessary API of the container, but … we use JavaScr...
What is the meaning of “non temporal” memory accesses in x86
...Policies and Performance, they can be considered as write-around (no-write-allocate, no-fetch-on-write-miss).
Finally, it may be interesting to review John McAlpin notes about non-temporal stores.
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How to pass parameters correctly?
...mally by copying the object (**)
(*) pointers may refers to dynamically allocated memory, therefore when possible you should prefer references over pointers even if references are, in the end, usually implemented as pointers.
(**) "normally" means by copy constructor (if you pass an object of th...
Convert a series of parent-child relationships into a hierarchical tree?
...verhead on parsing recursive functions/calls. If there's no explicit stack allocation, I'd take iteration over recursion every day.
– user719662
Sep 17 '18 at 8:41
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Please explain the exec() function and its family
... for the child and all the data would have been copied to child’s pages. Allocating new memory and copying data is a very expensive process(takes processor’s time and other system resources). We also know that in most cases, the child is going to call exec() and that would replace the child’s ...