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What are the differences between struct and class in C++?
...(11.2):
Member of a class defined with the
keyword class are private by
default. Members of a class defined
with the keywords struct or union
are public by default.
Additional difference: the keyword class can be used to declare template parameters, while the struct keyword cannot be s...
Grouped LIMIT in PostgreSQL: show the first N rows for each group?
I need to take the first N rows for each group, ordered by custom column.
5 Answers
5
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How to sort an array of objects by multiple fields?
...ngs during the comparison. I have not done any profiling though.
var sort_by;
(function() {
// utility functions
var default_cmp = function(a, b) {
if (a == b) return 0;
return a < b ? -1 : 1;
},
getCmpFunc = function(primer, reverse) {
...
Why is a ConcurrentModificationException thrown and how to debug it
I am using a Collection (a HashMap used indirectly by the JPA, it so happens), but apparently randomly the code throws a ConcurrentModificationException . What is causing it and how do I fix this problem? By using some synchronization, perhaps?
...
How do you find the disk size of a Postgres / PostgreSQL table and its indexes
...Oracle and looking for a way to find the table and index size in terms of bytes/MB/GB/etc , or even better the size for all tables. In Oracle I had a nasty long query that looked at user_lobs and user_segments to give back an answer.
...
What is meant by “managed” vs “unmanaged” resources in .NET?
What is meant by the terms managed resource and unmanaged resource in .NET? How do they come into the picture?
5 Answers
...
HTTP GET with request body
...t body with GET but it should not have any meaning. If you give it meaning by parsing it on the server and changing your response based on its contents, then you are ignoring this recommendation in the HTTP/1.1 spec, section 4.3:
...if the request method does not include defined semantics for an en...
Why use a prime number in hashCode?
...
Because you want the number you are multiplying by and the number of buckets you are inserting into to have orthogonal prime factorizations.
Suppose there are 8 buckets to insert into. If the number you are using to multiply by is some multiple of 8, then the bucket inser...
How to determine CPU and memory consumption from inside a process?
...llTotalPageFile - memInfo.ullAvailPageFile;
Virtual Memory currently used by current process:
#include "windows.h"
#include "psapi.h"
PROCESS_MEMORY_COUNTERS_EX pmc;
GetProcessMemoryInfo(GetCurrentProcess(), (PROCESS_MEMORY_COUNTERS*)&pmc, sizeof(pmc));
SIZE_T virtualMemUsedByMe = pmc.Private...
Forced naming of parameters in Python
...
You can force people to use keyword arguments in Python3 by defining a function in the following way.
def foo(*, arg0="default0", arg1="default1", arg2="default2"):
pass
By making the first argument a positional argument with no name you force everyone who calls the function...