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Finding the type of an object in C++
I have a class A and another class that inherits from it, B. I am overriding a function that accepts an object of type A as a parameter, so I have to accept an A. However, I later call functions that only B has, so I want to return false and not proceed if the object passed is not of type B.
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Python Create unix timestamp five minutes in the future
...etime.timedelta) didn't mention that shortcut. It only had days, seconds, and microseconds.
– Daniel Rhoden
May 5 '10 at 19:05
12
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How to select last two characters of a string
...pe.substr(…) is not strictly
deprecated (as in "removed from the Web standards"), it is considered
a legacy function and should be avoided when possible. It is not part
of the core JavaScript language and may be removed in the future.
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How can you undo the last git add?
...valid ref. I haven't committed anything yet (new repo) just done git add . and regretted it. I don't want to reset the entire add, just one directory. git reset -- dir/*.* generates the error above.
– Francis Davey
Jan 23 '14 at 17:51
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Is gcc std::unordered_map implementation slow? If so - why?
... performance critical software in C++. There we need a concurrent hash map and implemented one. So we wrote a benchmark to figure out, how much slower our concurrent hash map is compared with std::unordered_map .
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How to access parameters in a RESTful POST method
...a JSON object instead of a string. Jersey uses JAXB to support marshaling and unmarshaling JSON objects (see the jersey docs for details). Create a class like:
@XmlRootElement
public class MyJaxBean {
@XmlElement public String param1;
@XmlElement public String param2;
}
Then your @POST ...
Fast check for NaN in NumPy
... to get slower as NaNs get closer to the start of the array. On the other hand, sum's throughput seems constant regardless of whether there are NaNs and where they're located:
In [40]: x = np.random.rand(100000)
In [41]: %timeit np.isnan(np.min(x))
10000 loops, best of 3: 153 us per loop
In [42]:...
Android get free size of internal/external memory
...urpose :
public static boolean externalMemoryAvailable() {
return android.os.Environment.getExternalStorageState().equals(
android.os.Environment.MEDIA_MOUNTED);
}
public static String getAvailableInternalMemorySize() {
File path = Environment.getDataDirecto...
Only using @JsonIgnore during serialization, but not deserialization
I have a user object that is sent to and from the server. When I send out the user object, I don't want to send the hashed password to the client. So, I added @JsonIgnore on the password property, but this also blocks it from being deserialized into the password that makes it hard to sign up users...
How can I write a regex which matches non greedy? [duplicate]
...o a trick you can do to work around this: Since \s means "any whitespace", and "\S" means "any non-whitespace", [\s\S] will match ANY character (like ".", but including new line)! Similarly, you could use [\d\D], or [\w\W]. This can be quite a handy little "hack", and it certainly a very useful tric...