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use of deleted function std::unique_ptr 编译错误剖析，你可能少了一个st...
use of deleted function std::unique_ptr 编译错误剖析，你可能少了一个std::move编译报错日志如下： usr include c++ 4 7 bits stl_construct h:77:7: error: use of deleted function & 39;std::unique_ptr<_Tp, _Dp>::unique_ptr(const std::unique_p 编译报错日志如下：
/usr/...
How to correctly implement custom iterators and const_iterators?
...e, std::iterator with random_access_iterator_tag.These base classes define all type definitions required by STL and do other work.
To avoid code duplication iterator class should be a template class and be parametrized by "value type", "pointer type", "reference type" or all of them (depends on impl...
Split string on the first white space occurrence
...tr.indexOf(' ')+1); // "tocirah sneab"
Note that if there is no space at all, then the first line will return an empty string and the second line will return the entire string. Be sure that is the behavior that you want in that situation (or that that situation will not arise).
...
How to check if a table exists in a given schema
... (like OIDs) gets lost in translation from the system catalogs - which actually carry all information.
System catalogs
Your question was:
How to check whether a table exists?
SELECT EXISTS (
SELECT FROM pg_catalog.pg_class c
JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace
WHE...
Set the value of a variable with the result of a command in a Windows batch file
...%a in ('command1 ^| command2') do set VAR=%%a.
– Bill_Stewart
Mar 4 '16 at 19:23
@Bill_Stewart you just saved my day, ...
cartesian product in pandas
...n unused column name, then add dummy columns with that name, merge, and finally drop the column on the result? Creating, as opposed to reading, data with pandas is just a pain
– Bananach
Oct 10 '19 at 7:31
...
How to check if all of the following items are in a list?
...
Operators like <= in Python are generally not overriden to mean something significantly different than "less than or equal to". It's unusual for the standard library does this--it smells like legacy API to me.
Use the equivalent and more clearly-named method, ...
List comprehension: Returning two (or more) items for each item
...bda x: x + 2
>>> g = lambda x: x ** 2
>>> list(chain.from_iterable((f(x), g(x)) for x in range(3)))
[2, 0, 3, 1, 4, 4]
Timings:
from timeit import timeit
f = lambda x: x + 2
g = lambda x: x ** 2
def fg(x):
yield f(x)
yield g(x)
print timeit(stmt='list(chain.from_itera...
搭建高可用mongodb集群（三）—— 深入副本集内部机制 - 大数据 & AI - 清...
...为1是不显示的，这里标示出来。
rs.conf();
{
"_id" : "rs0",
"version" : 9,
"members" : [
{
"_id" : 0,
"host" : "192.168.1.136:27017" },
{
...
Substitute multiple whitespace with single whitespace in Python [duplicate]
...ce characters that are combined.
To match unicode whitespace:
import re
_RE_COMBINE_WHITESPACE = re.compile(r"\s+")
my_str = _RE_COMBINE_WHITESPACE.sub(" ", my_str).strip()
To match ASCII whitespace only:
import re
_RE_COMBINE_WHITESPACE = re.compile(r"(?a:\s+)")
_RE_STRIP_WHITESPACE = re.co...