大约有 17,000 项符合查询结果(耗时:0.0385秒) [XML]

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Why can't I define a default constructor for a struct in .NET?

...ublic struct Tempo { const double DefaultBpm = 120; private double _bpm; // this field must not be modified other than with its property. public double BeatsPerMinute { get => _bpm + DefaultBpm; set => _bpm = value - DefaultBpm; } } This is different than...
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Can I call memcpy() and memmove() with “number of bytes” set to zero?

... From the C99 standard (7.21.1/2): Where an argument declared as size_t n specifies the length of the array for a function, n can have the value zero on a call to that function. Unless explicitly stated otherwise in the description of a particular function in this subclause, pointer argume...
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Django South - table already exists

... Although the table "myapp_tablename" already exists error stop raising after I did ./manage.py migrate myapp --fake, the DatabaseError shows no such column: myapp_mymodel.added_field. Got exactly the same problem! 1.Firstly check the migration...
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What kind of leaks does automatic reference counting in Objective-C not prevent or minimize?

...chain referring back to an earlier object. It is for this reason that the __unsafe_unretained and __weak ownership qualifiers exist. The former will not retain any object it points to, but leaves open the possibility of that object going away and it pointing to bad memory, whereas the latter doesn...
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What is a “callback” in C and how are they implemented?

...y're implemented using function pointers. Here's an example: void populate_array(int *array, size_t arraySize, int (*getNextValue)(void)) { for (size_t i=0; i<arraySize; i++) array[i] = getNextValue(); } int getNextRandomValue(void) { return rand(); } int main(void) { int m...
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Why does the MongoDB Java driver use a random number generator in a conditional?

... laws it is a trivial observation that this piece of code amounts to if (!_ok && Math.random() <= 0.1) return res; The commit that originally introduced this logic had if (_ok == true) { _logger.log( Level.WARNING , "Server seen down: " + _addr, e ); } else if (Math.random() < 0...
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Python pandas: fill a dataframe row by row

... I see. So the loc attribute of the data frame defines a special __setitem__ that does the magic I suppose. – xApple Jun 13 '13 at 16:24 ...
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How do I check if an array includes a value in JavaScript?

...ilar methods: jQuery: $.inArray(value, array, [fromIndex]) Underscore.js: _.contains(array, value) (also aliased as _.include and _.includes) Dojo Toolkit: dojo.indexOf(array, value, [fromIndex, findLast]) Prototype: array.indexOf(value) MooTools: array.indexOf(value) MochiKit: findValue(array, val...
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Print string to text file

... text_file = open("Output.txt", "w") text_file.write("Purchase Amount: %s" % TotalAmount) text_file.close() If you use a context manager, the file is closed automatically for you with open("Output.txt", "w") as text_file: t...
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Unresolved specs during Gem::Specification.reset:

...t turned out to be a missing line in the gemspec file: $:.push File.expand_path("../lib", __FILE__) This line is normally at the top of the file (in many of the gems I have recently been working in) and I had commented it out to see why. ...