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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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C/C++ check if one bit is set in, i.e. int variable
... there such a way to check if bit 3 in temp is 1 or 0 without bit shifting and masking.
21 Answers
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Iterator invalidation rules
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C++17 (All references are from the final working draft of CPP17 - n4659)
Insertion
Sequence Containers
vector: The functions insert, emplace_back, emplace, push_back cause reallocation if the new size is greater than the old capa...
Prepend a level to a pandas MultiIndex
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This is especially nice for adding a level to the columns by adding axis=1, since the df.columns doesn't have the "set_index" method like the index, which always bugs me.
– Rutger Kassies
Feb 10 '17 a...
Is there a way to perform “if” in python's lambda
...eason to use a lambda, period. Assigning a lambda to a variable -- as a stand-in for def -- is generally a Very Bad Idea (tm). Just use a def so mere mortal programmers can read, interpret, understand and maintain it.
– S.Lott
Oct 18 '09 at 22:15
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sed or awk: delete n lines following a pattern
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how to delete all lines after the pattern is matched ? I am using sed -e '/<!--#content end--></div>/,$d' out.txt but it gives error saying : sed: -e expression #1, char 24: extra characters after command Thanks in advance.
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Access object child properties using a dot notation string [duplicate]
...(r, "b.b2"));
//-> 99
Although there are answers that extend this to "allow" array index access, that's not really necessary as you can just specify numerical indexes using dot notation with this method:
getDescendantProp({ a: [ 1, 2, 3 ] }, 'a.2');
//-> 3
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TextView.setTextSize behaves abnormally - How to set text size of textview dynamically for different
Calling TextView.setTextSize() is working abnormally. Right after the call to setTextSize if we get a getTextSize its returning a much higher value that what we set it to earlier.
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OnNotify函数 ON_NOTIFY消息总结 - C/C++ - 清泛网 - 专注C/C++及内核技术
...的消息映射，然后调用。(checks the message map for notification handlers to call.)。
一般说来，你不用重载OnNotify。你可以写一个处理函数，然后添加消息映射（这个就不用详解了吧）。
当然，也可以通过重载OnNotify函数处理指定控件的...
How do you set a default value for a MySQL Datetime column?
... need to ALWAYS specify a value for this column or the value will automatically reset itself to "now()" on update. This means that if you do not want the value to change, your UPDATE statement must contain "[your column name] = [your column name]" (or some other value) or the value will become "now(...