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Why is early return slower than else?
...984281521812363]
>>> T(lambda : with_else()).repeat()
[0.36009842032996175, 0.28962249392031936, 0.2927151355828528]
>>> T(lambda : without_else(True)).repeat()
[0.31709728471076915, 0.3172671387005721, 0.3285821242644147]
>>> T(lambda : with_else(True)).repeat()
[0.309398...
What are the rules for the “…” token in the context of variadic templates?
...template parameter pack if it appears on the right side of an expression (call this expression pattern for a moment), or it's a pack argument if it appears on left side of the name:
...thing // pack : appears as template arguments
thing... // unpack : appears when consuming the arguments
The ru...
What is the most efficient/elegant way to parse a flat table into a tree?
...
Now that MySQL 8.0 supports recursive queries, we can say that all popular SQL databases support recursive queries in standard syntax.
WITH RECURSIVE MyTree AS (
SELECT * FROM MyTable WHERE ParentId IS NULL
UNION ALL
SELECT m.* FROM MyTABLE AS m JOIN MyTree AS t ON m.ParentI...
CDC:DrawText 多行显示文本(文本自动换行) - C++ UI - 清泛IT社区,为创新赋能!
... LPRECT lpRect, // formatting dimensions
UINT uFormat // text-drawing options
);复制代码参数:
hdc:设备环境句柄。
lpString:指向将被写入的字符串的指针,如果参数nCount是C1...
How can I force Powershell to return an array when a call only returns one object?
...
I actually feel like this is the most clear and safe option. You can reliably use ".Count - ge 1' on the collection or 'Foreach'
– Jaigene Kang
Jul 11 '17 at 22:24
...
控件重绘函数/消息OnPaint,OnDraw,OnDrawItem,DrawItem的区别 - C/C++ - 清...
...让子类自己有一个处理的机会OnCtlColor (CDC* pDC, CWnd* pWnd, UINT nCtlColor)pDC,pWnd都是于子类相关的,在这里可以设置,前景颜色,背景颜色,画刷类型,字体等等,但不能改变元素的界面框架,这是DrawItem 所能干的。如果同时有DrawItem...
What's “wrong” with C++ wchar_t and wstrings? What are some alternatives to wide characters?
...e wchar_t is a distinct type whose values can represent distinct codes for all members of the largest extended character set specified among the supported locales (22.3.1).
...
Is there a way to instantiate objects from a string holding their class name?
...initializing or assigning to it. Have a look at its documentation here. Finally, the use of a raw function pointer is also a bit oldish. Modern C++ code should be decoupled from specific functions / types. You may want to look into Boost.Function to look for a better way. It would look like this the...
How do I get around type erasure on Scala? Or, why can't I get the type parameter of my collections?
...hese instances are objects, you can pass them around, store them, and generally call methods on them. With the support of implicit parameters, it becomes a very powerful tool. Take the following example, for instance:
object Registry {
import scala.reflect.Manifest
private var map= Map.empty[...
JSON datetime between Python and JavaScript
...
The lambda can be adapted to call the base implementation on non-datetime types, so TypeError can be raised if needed: dthandler = lambda obj: obj.isoformat() if isinstance(obj, datetime) else json.JSONEncoder().default(obj)
– Pascal...
