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What are the details of “Objective-C Literals” mentioned in the Xcode 4.4 release notes?
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This part is new. Expression Literals
When you have an expression (M_PI / 16 for example) you should put it inside parenthesis.
This syntax works for numeral expressions, booleans, finding an index in a (C-) string, boolean values, enum constants, and even character strings!
NSNumber *piO...
Print current call stack from a method in Python code
...port traceback
def f():
g()
def g():
for line in traceback.format_stack():
print(line.strip())
f()
# Prints:
# File "so-stack.py", line 10, in <module>
# f()
# File "so-stack.py", line 4, in f
# g()
# File "so-stack.py", line 7, in g
# for line in traceback.form...
Update MongoDB field using value of another field
...; {
requests.push( {
'updateOne': {
'filter': { '_id': document._id },
'update': { '$set': { 'name': document.name } }
}
});
if (requests.length === 500) {
//Execute per 500 operations and re-init
db.collection.bulkWrite(requests)...
What is the reason not to use select *?
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If your code depends on the columns being in a specific order, your code will break when there are changes to the table. Also, you may be fetching too much from the table when you select *, especially if there is a binary field in the table.
Just because you are using all the col...
What's the point of Spring MVC's DelegatingFilterProxy?
...lements Filter interface in applicationContext, and i want to execute in a order, then how can i make it?
– Abhishek Nayak
Nov 26 '14 at 12:45
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How does this code generate the map of India?
... character. In the second, decimal 33 is ASCII for '!'. Toggling the low-order bit of 33 gives you 32, which is ASCII for a space. This causes ! to be printed if b is odd, and a blank space to be printed if b is even. The rest of the code is simply there to walk the "pointer" a through the strin...
What is the use of having destructor as private?
...e connection being open or a file being written. You could have a "request_delete" method in the class or the manager that will check that condition and it will either delete or decline, and return a status telling you what it did. That's far more flexible that just calling "delete".
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How to initialize std::vector from C-style array?
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Don't forget that you can treat pointers as iterators:
w_.assign(w, w + len);
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How do I raise the same Exception with a custom message in Python?
...Note that you can add whatever you like to err. For example err.problematic_array=[1,2,3].
Edit: @Ducan points in a comment the above does not work with python 3 since .message is not a member of ValueError. Instead you could use this (valid python 2.6 or later or 3.x):
try:
try:
raise...
Subclassing a Java Builder class
...f class that can call all the builder methods on any of its parents in any order:
public final class LeafClass extends SecondLevel {
private int baz;
public static final class Builder extends SecondLevel.Builder<LeafClass,Builder> {
protected LeafClass createObject() {
...