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Confused about __str__ on list in Python [duplicate]
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Python has two different ways to convert an object to a string: str() and repr(). Printing an object uses str(); printing a list containing an object uses str() for the list itself, but the implementation of list.__str__() calls repr() for the individual it...
What does the thread_local mean in C++11?
I am confused with the description of thread_local in C++11. My understanding is, each thread has unique copy of local variables in a function. The global/static variables can be accessed by all the threads (possibly synchronized access using locks). And the thread_local variables are visible to...
Java - sending HTTP parameters via POST method easily
...;param2=b&param3=c";
byte[] postData = urlParameters.getBytes( StandardCharsets.UTF_8 );
int postDataLength = postData.length;
String request = "http://example.com/index.php";
URL url = new URL( request );
HttpURLConnection conn= (HttpURLConnection) url.openConnecti...
Object-orientation in C
...It tries to keep minimal the available concepts for the sake of simplicity and flexibility: uniform object oriented programming including open classes, metaclasses, property metaclasses, generics, multimethods, delegation, ownership, exceptions, contracts and closures. There is a draft paper (PDF) ...
Precise Financial Calculation in JavaScript. What Are the Gotchas?
... that the JavaScript lexer reads the string "0.1" from the source and then converts it to a binary floating point and then you already did an unintended rounding. The problem is about representation (binary vs decimal) not about precision.
– mgd
Nov 20 '15 at 1...
C++ mark as deprecated
...for this all I got was a Microsoft specific solution; #pragma deprecated and __declspec(deprecated) .
7 Answers
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In STL maps, is it better to use map::insert than []?
...es in STL maps . I preferred map[key] = value; because it feels natural and is clear to read whereas he preferred map.insert(std::make_pair(key, value)) .
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Is char signed or unsigned by default?
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The book is wrong. The standard does not specify if plain char is signed or unsigned.
In fact, the standard defines three distinct types: char, signed char, and unsigned char. If you #include <limits.h> and then look at CHAR_MIN, you can find...
What's the best way to iterate over two or more containers simultaneously
...ften in your data, consider using another pattern which zips two sequences and produces a range of tuples, corresponding to the paired elements:
for (auto& [a, b] : zip(containerA, containerB)) {
a = b;
}
The implementation of zip is left as an exercise for the reader, but it follows easi...
Throwing cats out of windows
...y write a little DP (dynamic programming) for the general case of n floors and m cats.
The main formula, a[n][m] = min(max(a[k - 1][m - 1], a[n - k][m]) + 1) : for each k in 1..n, should be self-explanatory:
If first cat is thrown from k-th floor and dies, we now have k - 1 floors to check (all...