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Split comma-separated strings in a column into separate rows
... use separate_rows:
separate_rows(v, director, sep = ",")
You can use the convert = TRUE parameter to automatically convert numbers into numeric columns.
4) with base R:
# if 'director' is a character-column:
stack(setNames(strsplit(df$director,','), df$AB))
# if 'director' is a factor-column:
sta...
What are copy elision and return value optimization?
...to a copy or move constructor is elided, that constructor must still exist and must be accessible. This ensures that copy elision does not allow copying objects which are not normally copyable, e.g. because they have a private or deleted copy/move constructor.
C++17: As of C++17, Copy Elision is gua...
Can a pointer to base point to an array of derived objects?
I went to a job interview today and was given this interesting question.
3 Answers
3
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How to set tint for an image view programmatically in android?
....setColorFilter(ContextCompat.getColor(context, R.color.COLOR_YOUR_COLOR), android.graphics.PorterDuff.Mode.MULTIPLY);
For Vector Drawable
imageView.setColorFilter(ContextCompat.getColor(context, R.color.COLOR_YOUR_COLOR), android.graphics.PorterDuff.Mode.SRC_IN);
UPDATE:
@ADev has newer soluti...
How to crop an image using C#?
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Is method DrawImageUnscaledAndClipped more efficient than DrawImage for cropping purpose?
– Ivan Kochurkin
Jan 4 '13 at 22:27
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BrightnessTools 拓展：设置手机亮度的工具 · App Inventor 2 中文网
...最大亮度，则返回 255。
注意：Android 系统规定最大值应为 255。
但是，不同品牌的手机设置不同，例如部分小米手机的最大值是 4000。
注册 Changed 的...
Incompatible implicit declaration of built-in function ‘malloc’
...y the reason for the warning. Ex: a x64 platform with 64-bit data pointers and 32-bit int values will puke goat feces, while a x86 32bit-data-pointer/32bit-int can seemingly work correctly. Neither are correct, as in neither case is the compiler aware of what malloc actually returns, and assumes int...
How to copy files from 'assets' folder to sdcard?
...red Dec 25 '10 at 12:43
Rohith NandakumarRohith Nandakumar
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How to remove part of a string? [closed]
...why this answer was posted, it's a lengthier duplicate of Dominic's answer and a shorter duplicate of Roland's answer...
– CPHPython
Jul 9 '18 at 9:02
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Mock vs MagicMock
My understanding is that MagicMock is a superset of Mock that automatically does "magic methods" thus seamlessly providing support for lists, iterations and so on... Then what is the reason for plain Mock existing? Isn't that just a stripped down version of MagicMock that can be practically ...