Jan 20, 2019 · struct A { A(const char *); auto operator<=>(const A&) const = default; }; template<A a> A operator ""_a(); In trying to understand what this feature is I've just learned that you can have numeric literal operator templates in C++, which make each digit of numerical constant be passed as a non-type argument to a template (cf. a better ...

Jan 12, 2014 · SELECT txt1 FROM T1 WHERE txt1 LIKE '_a%' will select records with txt1 values of 'xa1', 'xa taco', 'ya anything really', etc. Now let's say you want to actually search for the percent sign. In order to do this you need a special character that indicates % should not be treated as a wildcard. For example: SELECT txt1 FROM T1 WHERE txt1 LIKE '_a\%'

Jan 6, 2013 · class SomeClass(object): def __init__(self, a=0): self._a = a self._b = 0 def __add__(self, other): result = self.__class__() result._b = self._a + other._a return result Now, I have an number of members like _b, such as _c and _d, so __add__ will need an extra line for each of these attributes. Being able to pass these on object instantiation ...

Dec 7, 2021 · No, both r%_ and r% don't actually mean the same thing. The first version r%_ will match any string starting with r, followed by zero or more of any character, followed by any single character.

Apr 26, 2014 · It is because of the Private name mangling.. Private name mangling: When an identifier that textually occurs in a class definition begins with two or more underscore characters and does not end in two or more underscores, it is considered a private name of that class.

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Nov 22, 2010 · It instead get a '_a list ref type. This mean that the type is not polymorphic, but merely unknown. Once you do something with a involving a particular type, it fixes '_a once and for all. # let a = ref [];; val a : '_a list ref = {contents = []} # let sum_of_a = List.fold_left (+) 0 !a;; val sum_of_a : int = 0 # a;; - : int list ref ...

May 22, 2012 · int x = ({ int _a = a++; int _b = b--; _a > _b ? _a : _b; }) This runs the side effects only once. But, to be honest, you should ditch that macro altogether and use an inline function, or even a non-inline function since, most of the time, the compiler can do a decent job of optimisation even without that suggestion.

Jun 24, 2014 · Assert position at the beginning of the string «^» Match a single character in the range between “a” and “z” «[a-z]{1}» Exactly 1 times «{1}» Match a single character present in the list below «[a-z0-9_]{3,13}» Between 3 and 13 times, as many times as possible, giving back as needed (greedy) «{3,13}» A character in the range between “a” and “z” «a-z» A character in ...

Jun 26, 2020 · If I define a Python class which has an instance field/variable __MAX_N, it seems Python applies this private name mangling thing. But if I rename it to __MAX_N__ then there's no mangling, and I can